At first, I thought that it was the raid that removed things from my house. but now new items are disappearing and villagers are disappearing.

We have stopped playing on the REALM because things are disappearing. Yesterday, my village lost over 15 villagers.

I have restored the REALM to Tuesday - April 23, before the 1.1.4 update and I have closed the REALM until this issue is resolved. We we cannot get it resolved, then I will cancel my REALM service.

On Realms all of my villagers in my iron farm just disappeared within about an hour. Iron farms need beds so I was curious whether this is related to the other bug that villagers can access beds without a valid path (i.e. through walls) or if the villagers were getting out of bed in the morning and clipping through walls. Please fix SOON as this breaks so much of the game.

Had this happen on a vanilla 1.14 server. 15+ villagers (sitting in minecarts) disappeared in my trading outpost after the server crashed twice. Thank god I had a backup...

The server log is full of these warnings:
"Keeping entity minecraft:llama_spit that already exists with UUID 9ce28ce2-a2eb-462b-9f68-61095cf2600e"

after eventually finishing it off with:
"Server Watchdog/FATAL A single server tick took 60.00 seconds (should be max 0.05)"
and crashing.

I am attaching the crash reports.

I am thinking going to the spawn chunk triggered the crash, because I was able to replicate the crash on singleplayer by going to the spawn chunk using the nether portal.

UPDATE: Since my villagers disappeared not long after a raid I decided to test this in my test world and sure enough, after I successfully defeated a raid I just managed to catch my last villager despawning (with that white puff of smoke).

I suspect the end of a raid has something to do with villagers disappearing but I don't know why. Either way, this makes Iron Farms horrendously vulnerable to raids...

Okay, Since Mojang said that this issue was resolved in  MC-150322 I decided to test it. I left my house to do some adventuring and on my return, I discovered that the following items were gone.

Diamond Pick Axe and item frame.

Diamond Axe and item frame.

Diamond Shovel and item frame.

Diamond Sword and item frame.

Gold Sword and item frame.

Diamond Armor on Armor Stand.

Leather Armor on Armor Stand.

Fishing Rod and item frame.

Two cats

Happened to me as well. Lost villagers, item frames, armor stands full of armor, and all of my maps. This is ridiculous. I’ve cancelled my subscription and I’m not playing again until I see that this has been resolved.

I'm using spigot 1.14 with several plugins so it might not be exactly this bug, but I felt I might as well share what I know because it most likely does relate. I'm the owner of an smp server. The server often crashes about once an hour, almost always due to https://bugs.mojang.com/browse/MC-148830. People have been reporting all sorts of entities from armor stands to named villagers disappearing, usually soon after the server starts up. Checking the history with CoreProtect, we found no logs of them dying, so we assume that they're despawning. To try and reproduce this, I placed 4 villagers in their own cells and logged off. I came back a few hours later, probably a crash in between, and the villagers were gone. I replenished their cells with 3 more villagers, leaving one empty on accident. I log off and return a few hours later, possibly after a crash, and the villagers are still there. I notice the empty cell and add a villager. I then teleport far away and place another villager in a new cell. I log off and after another server crash, I return to see the villager I placed most recently is still there. I teleport back to the place with the original villagers and find the three villagers which were there for a while had despawned, while the last villager was still there. This bug is affecting many of my servers' players. I really hope you patch it for 1.14.1.

I'm having mobs, entities, like item frames, tamed horses, named tagged mobs, tamed wolves, parrots, and villagers keep constantly disappearing on my 1.14 server when ever the server needs a restart or crashes and is started back up.

I wrote a post about it here on Spigot Forums:

https://www.spigotmc.org/threads/1-14-spigot-mobs-entities-despawning-after-server-restarts.371523/#post-3389961

Over the weekend, my girlfriend and I played 1.14 in peaceful mode on my realm, so we could work on our villages. We kept a strict account of everything in our villages and our houses as we added the new villager tools and NOTHING disappeared and NOTHING despawned.

Please use this information accordingly.

 - brad

This is happening to me as well on my 1.14 vanilla server (NO SPIGOT). Whenever the server restarts, things like brewing stands disappear. We also have a name-tagged endermite in a minecart in The End. This endermite+the minecart has disappeared after certain reboots. Hope this is helpful. 

CORRECTION - I have made some edits to the original comment. This issue is kind of sporadic and unpredictable when these entities get reset. I wish I could be more helpful but I don't know what the cause of the problem is :/ . My player who experienced the issue with the endermite thinks it has something to do with a chunk loading while the server was reset (possible race condition thing?) I didn't do a hard-shutdown either, I let the server gracefully shutdown using the restart command in multicraft. 

Happening on my 1.14 Spigot server, we have essentials and treecapitator (both 1.13 but they're still functional). No issues in reproducing with or without plugins though.

We noticed it at first when it was on hard and there were no mob spawns, and our cows were acting strangely. The cows moved in very small amounts every few seconds, it was as if the whole server was tick lagging but everything except the mobs were fine. After restarting our cows are gone. They have been bred and interacted with, so that's out of the question.

Using paper-3 for 1.14, I noticed this in my console logs:

[15:58:05 ERROR]: Keeping entity minecraft:cow that already exists with UUID 58b95fe6-e708-4767-af72-c5acc2872aa3 [15:58:05 ERROR]: Deleting duplicate entity EntityCow['Cow'/7883, uuid='58b95fe6-e708-4767-af72-c5acc2872aa3', l='world', x=3572.00, y=80.00, z=7455.00, cx=223, cz=465, tl=626, v=false, d=false] [15:58:05 ERROR]: Keeping entity minecraft:cow that already exists with UUID 89ceaef9-2bce-421d-a916-4b7d4ee86062 [15:58:05 ERROR]: Deleting duplicate entity EntityCow['Cow'/7884, uuid='89ceaef9-2bce-421d-a916-4b7d4ee86062', l='world', x=3570.00, y=80.00, z=7455.00, cx=223, cz=465, tl=626, v=false, d=false] [15:58:05 ERROR]: Keeping entity minecraft:cow that already exists with UUID fc1099d8-5b05-41a4-9e25-e181aaa435b3 [15:58:05 ERROR]: Deleting duplicate entity EntityCow['Cow'/7885, uuid='fc1099d8-5b05-41a4-9e25-e181aaa435b3', l='world', x=3571.00, y=80.00, z=7455.00, cx=223, cz=465, tl=626, v=false, d=false] [15:58:05 ERROR]: Keeping entity minecraft:cow that already exists with UUID fa9f003c-b1d1-4c09-b0ca-cb38e41a5a2a [15:58:05 ERROR]: Deleting duplicate entity EntityCow['Cow'/7886, uuid='fa9f003c-b1d1-4c09-b0ca-cb38e41a5a2a', l='world', x=3573.00, y=80.00, z=7454.00, cx=223, cz=465, tl=626, v=false, d=false][15:58:07 ERROR]: Keeping entity minecraft:pig that already exists with UUID b8e4cfab-8793-43af-8cdc-17836d96025e [15:58:07 ERROR]: Deleting duplicate entity EntityPig['Pig'/7918, uuid='b8e4cfab-8793-43af-8cdc-17836d96025e', l='world', x=3494.13, y=64.00, z=7438.51, cx=218, cz=464, tl=6943, v=false, d=false]

Teleporting to these coordinates, I sometimes found the entity still there and sometimes did not find the entity there. I'm wondering if this has to do with the bug.

Is mojang gonna address this or keep removing duplicate bug reports and sit on their hands? 

Seriously the update is about the village and pillage update and they aren't doing wack about it.

Had this happen twice,  to villagers and to  hopper minecarts. Both times in the End dimension, on a self-hosted completely vanilla survival server.

It seems to affect ones in a single chunk specifically, villagers in the chunk right next to the ones who disappeared were fine, while everyone in one chunk disappeared.

This is a very severe bug, I'm scared of even playing at the moment, there are seriously difficult to replace entities in some of my builds, and it seems to be a common issue: https://www.reddit.com/r/Minecraft/search?q=disappearing&restrict_sr=on&sort=relevance&t=month

It seems to happen when chunks are unloaded/loaded, probably the worst bug in 1.14, the visual glitching is annoying, but it doesn't result in permanent damage to player worlds.

This is a serious issue!! My game is unplayable while this bug is not addressed-- I have lost over half my population of villagers in multiple villages.  When will Mojang acknowledge/address this???

Today I lost a Mending/Silk Touch Villager (very cheap trades, too, at 2 and 3 emeralds each) and about 14 other Villagers. I have consistently been losing item frames, armor stands, and mobs. I would love for this issue to be resolved.

Happened on a vanilla SMP server I was running. Lost all of my chickens, all but one of my cows, and half of my sheep.  I'm holding off on my villager trading hall until at least 1.14.1, and possibly after this issue gets confirmed resolved by others.

KaptainWutax has investigated this a bunch, and he believes he understands the cause. Quoting him:

Tons of people are reporting to me that their villagers are disappearing in their iron farms. The error is ALWAYS a position desync, of this format : Wrong location! (-65, 4) should be (-54, 13), avk['Villager'/172716, l='world', x=-1037.30, y=89.00, z=70.30]. Some are related to sleeping on chunk borders(reproduceable consistently), and some seem completely random, in the center of chunks.

Here's a link to a video of the reproducible occurrence: https://streamable.com/0ivkh

The bug in Timothy's video is not the same as the original issue. Timothy's video shows villagers who are sleeping on beds. The issue we have been talking about is for all entities, even the ones that can't sleep on beds. I'd also like to mention that I have had villagers despawn who were trapped in a 1x1 block with no bed nearby.

Thanks to @unknown's comment, I can confirm that villagers can indeed disappear, if they have been dislocated from their bed.

I assume that this relocation issue not only happens in that specific circumstance, it's just an easy one to reproduce. Maybe this can also happen if the villager/entity is moving while the chunk is saved? Just an assumption though.

My server (1.14 and then later 1.14.1 Pre-2) has had this issue with all kinds of Entities (Item Frames, Minecarts, Armour Stands, Villagers)

It seems to be based on the chunk? Whereby all Entities in the chunk disappear upon loading the server, as I had Item Frames on two very different Y coords in the same chunk as well as Armour Stands (again in the same chunk) all disappear at the same time.

 
EDIT: Just happened again, does indeed seem to be chunk based (all item frames in the right hand chunk vanished, while the ones on the right did not)

I think testing could be done whether or not the amount of entities in a chunk makes the random disappearances more likely, it may be that a single bad entity causes all in the chunk to disappear, in that case chunks with more entities would be more at risk. All the disappearances I have noticed happened in chunks with plenty of entities, though this may just be because those are the easiest cases to notice.

I tested with the villager bed bug: it doesn't cause other entities in either chunk to disappear, just the villager. This seems to suggest that it and the whole chunk disappearances are separate issues.

I have also seen some talk about a possible third issue, which causes villagers to teleport into floor/walls and die from damage, rather than just disappearing.

The whole-chunk issue also affects item frames, which are immobile, and in my case affected stationary hopper minecarts, which weren't even on rails, so I don't think they have to do with motion. In my case they have happened near end gateways, but that may be just be because of the chunks were often unloaded/loaded.

Hmm. I have just tested this with a chunk section full with item frames (2048 item frames in a single chunk section), and none of them disappeared when the world was reloaded.

The Bug happend after the server restart or crash in all of the loaded chunks

Has anyone had a whole-chunk entity wipe happen in a singleplayer world?, everyone seems to be talking about realms and servers. I think whole-chunk resets could be a server-specific issue.

This is just guesswork at this point, but maybe there is a specific type of entity that triggers the chunk entity wipes? Most of these problems seem to involve villagers, all incidents I have suffered from were in chunks that were loaded/unloaded with villagers in/near them.

Also, the rate for this happening seems to be pretty low, so one may need to fill multiple chunks with entities and repeatedly load/unload them.

I've had entities disappear, as well as villagers in walls and dying. 

It happens whenever the chunk gets loaded/unloaded. Both singleplayer world and multiplayer vanilla server.

Easily reproducible, spawn some entities cause chunk to unload/load and it's pretty much a guarantee any random amount of entities will be dusted.  

Ive had players lose over 200+ item frames, all their breeded animals, cows, sheeps, pigs, horses, llamas, etc. And also villagers are disappearing.

I can confirm this on my vanilla server, too.

Keeping entity minecraft:[insert one of many entities here] that already exists with UUID"

I also believe this causes the tick lag leading to:
"Server Watchdog/FATAL A single server tick took 60.00 seconds (should be max 0.05)"
and crashing.

Even when I increased the max tick time well past 10 minutes the server will crash (meaning it's already crashed without Watchdog).

This one is a seriously nasty bug.

idk if is the same bug but in my vanilla 1.14 the leashes attached with animals are disappearing.

Having the same issue on a Spigot 1.14 server. Animals, no matter if they're tamed or named or not keep getting deleted.
The only difference I see is I'm not getting the console log "Keeping entity minecraft:xy that already exists with UUID"

 I can provide the latest log if you want to.

Cory? I don't know if this helps at all, but I noticed early on (on the very first 1.14 snapshot last year) that the very FIRST entity that was throwing an error when booting up our server was the RABBIT (already exists). I ignored it, and did not report. But it kinda looks like that was the first glitchy bit? Dunno, but thought to comment nonetheless.
🙂
Momibelle

I had a moment that I could not find a cow entity while there where 20 cow's before me

/data get entity @e[type=minecraft:cow, limit=1]

-> no entity was found

I could not kill them with an arrow

I restarted the server and all cow's and other mobs where gone around my base

This issue is also occurring on my smp spigot server. I've had cows, villagers, item frames, name tagged zombies, and mine carts also disappear. I did noticed however that they only seem to disappear within specific chunks. Like I noticed that the item frames that did disappear were all in one chunk while others were randomly left untouched. I also would like to mention that not all of the entities in my base disappeared. Some of the villagers that were in other chunks did not disappear and not all of the item frames disappeared either.

Please don't post a comment here if you're using non-vanilla software. Spigot is third-party software and not supported by Mojang.

That makes no sense. Multiplayer spigot and bukkit use your code as the base of the jar's.
They may be third party but they use your code. So if the problem happens in vanilla it happens in multiplayer..............

Well, with 1.14.1 out I made a 1.14.1 server with the latest dev spigot for it. I restarted the test server I made on my pc a few times over and over again and no mobs or entities have not disappeared so far. I put some animals, villagers, some tamed around near spawn, and some over 1,000 blocks away. Everything seems to work so far.

Update: I updated my other server to 1.14.1 Everything seems to be going well after a few restart tests.

• After updating to 1.14.1 and starting server back up all the mobs/entities stayed.

• 1st Restart all mobs/tamed pets I checked all stayed around the world except for the ones around me.

• 2nd Restart I respawned mobs around me before restarting again, after the restart all mobs stayed around me and around the world.

• 3rd Restart everything stayed without disappearing.

So far mobs/entities seem to not disappear anymore on 1.14.1 Spigot.

Just did some testing myself in 1.14.1 and restarted a bunch of times. No disappearances.... until my 10th or so restart. The issue is still confirmed as existing in 1.14.1 for me.

With MC-151825 marked as duplicate, the affected versions should include 1.14.1

and what about Bedrock 1.11.1?
I have that problem in THAT version.

This ticket is only about the issue in Java Edition. If you're experiencing a similar issue in Bedrock Edition, please create a new ticket in the MCPE project.

Still having issues, minecraft village and pillage is unplayable as the updates main use is to interact with villagers. Is mojang addressing this?

This happened on our vanilla minecraft server after we did a reset according to instructions here (https://bugs.mojang.com/browse/MC-142134) to fix a lighting bug that has been recurring.  One time some farmland and slabs went missing, as well as some signs and some villagers (note that we ruled our creeper explosion due to the nature of missing blocks).  After another restart, the signs were back but not the rest.  One other time, some item frames went missing.

Is it possible these two bugs are related?

In 1.14 I was having issues finding certain villagers and they were breeding resulting in new villagers taking the workstation of old ones and the old ones were reappeaeing later. Now in 1.14.1 they are disappearing and not coming back. It has decimated my village and I am losing all villagers, feeding them bread to breed new ones which are not taking jobs resulting in slowly losing the working population. They also no longer congregate at the village center and wander towards the outside edge of one corner. 

The few ones with jobs left had their job block taken by new villagers when they disappeared so they do not go to the work block. there are none left assigned to any job station. 1.14 worked better. I have not encountered such buggy a update since the early days secret friday updates. This feels like a pre-release update( I usually found those to be buggy so never used them on a non test world) 

I have explored sufficient to verify they are not wandering off. The village is on the border of a jungle, birch forest, and plains.

I noticed disappearing after a trader visited. 

I can confirm this happening on my server. I did notice the errors (as mentioned above) in console from 1.14 on, but I didn't notice any entities disappearing. It wasn't until we updated to 1.14.1 that mass amount of entities started disappearing. The issue seems to occur every time the server restarts. 

Just happened on my single player world. Came back from a horse trip to see the following:

• all my chicken have disappeared from the pen. Every single one. There were still eggs lying there however.

•  2 dogs

• at least a villager (couldnt find his trade anymore)

• one llama

I checked the borders, I remembered the spots I put the dogs on, and it looks like both of them were on chunk borders. The chicken farm also had a block near a chunk border, but Im not sure if that has to do anything with it

Update: My minecraft server just crashed on me and everything has disappeared! This is on Minecraft Version 1.14.1!

So the bug is still happening!

All tamed mobs, boats, minecarts, everything have all disappeared after the crash!

With what I'm seeing from many players, with the bug happening in single player and multiplayer. It's kind of taking the fun out of the game when we can't even farm mobs or have tamed mobs around when everything just disappears on us. Also annoying when having item frames with items in it disappear or minecarts used for redstone farms.

1.14 & 1.14.1 is just not as playable as 1.13-1.13.2 was with this major bug going on.

This is a huge problem on our server. People are really fed up with villagers itemframes and minecarts etc disappearing

I can confirm that this bug isn't fixed. It affects 1.14.1. Please, reopen.

Valicon, the fix is listed as 1.14.2 Pre-Release 1, not 1.14.1. The bug is known to affect 1.14.1. 

@Valicon it is fixed in next pre-release

This seems to be fixed properly. The problem was that some entities triggered chunk processing and forced chunks to unload while the entity ticking phase was still going on. This led to all entities within that chunk to not unload properly, leaving them in memory. Then, when the chunk was reloaded, it caused duplicates.

In 1.14.2 pre1, unloading has been moved to a different queue, meaning this should never happen again. 😃

Has this fix been applied to the bedrock code base as well? Same issues are occurring there as well

This is the bug tracker for Java Edition. The developers or Java Edition don't do fixes for Bedrock Edition.

I have just conected to my own world and all my villagers are gone except one. This may nos be resolved...

@unknown, in which version of the game are you playing?

My animals are disappearing from my villages.  All of my sheep, pigs, llamas, dogs, cats, cows.  Very annoying.    I've repopulated one of the villages three times now and now I'm just tired of doing it.  I'm using 1.14.1.

Do I need to update to Minecraft 1.14.2 Pre-Release 1?

@Darkfelle soonish 1.14.2 release should come out but in 1.14.2 pre 1 was it fixed.

Thanks for getting back to me so quickly.

Having villagers despawn in 1.14.2 full release still. My fletcher and armorer vanished without a trace in a fully walled and lit up village

I am currently having this issue.  I have updated to 1.14.2 with a new world and with my old previous 1.14 world and all villagers in any visited village walled off, unwalled off, or villagers locked in lit houses have despawned.  I also died and lost all equipment before the 5 minute limit, when I was less than 10 blocks away.  Used the xray and watched it disappear as i mined to 5 blocks away.

Bug is still active. My multiplayer server is running on 1.14.2 full release on a JE vanilla server.

7 item frames vanished yesterday. All item frames were from the same chunk. However there was an 8th frame in the chunk that was not deleted. The only difference is the one item frame that remained had a Woodland Mansion map displayed on it. The missing 7 all had enchanting books.

Additionally the same day 3 armor stands vanished from the same chunk. Armor type does not appear to affect it, chain mail, gold and diamond sets were on each.

I can also confirm bug is still active in 1.14.2. Random mobs are disappearing from our world. A mending villager in a completely boxed off and slabbed area just disappeared on us in 1.14.2. Extremely frustrating. 

I do see this message spammed in my console constantly:

Fetching addpacket for removed entity. 

Mods, can you please re-open this ticket?

Based on this comment by @unknown it seems rather unlikely that the same issue has appeared again. Therefore, this is probably a different issue from the one before that causes similar effects.

Please create another ticket if you still experience the same issue. Make sure to include as much information as possible in that ticket and mention in that ticket's description that I told you to create a new one.

Can confirm this for 1.14.2

had 16 villagers in boats on a server completely safe. flew a few chunks away and when i flew back 4 of them had disappeared

Can confirm for 1.14.2.

So far can only confirm 6 named Zombie Pigmen and 4 Villagers have disappeared. The beds of the Villagers that have disappeared are set to Occupied and have to be replaced to work again.

Will report if we find more missing things!

Can this be re-checked? I couldn't find a related post if it has been created yet...

Based on this comment by @unknown it seems rather unlikely that the same issue has appeared again. Therefore, this is probably a different issue from the one before that causes similar effects.

Please create another ticket if you still experience the same issue. Make sure to include as much information as possible in that ticket and mention in that ticket's description that I told you to create a new one.

For those coming to post about this issue, as violine1101 noted it seems to be fixed. If you're still encountering vanishing villagers, check out MC-153904 instead.

I'm getting the "Fetching addpacket for removed entity."

I have not had anyone on our server complain about villagers going missing (yet) but I have heard players tell me doors have gone missing and I personally have placed the same door 3 times now...it's disappeared twice. I'm posting here because the other thread is specific to villagers, but my server is still encountering other things disappearing. I really think this needs to be reopened unless some further work has been done on it for the 1.14.3 update already.

Edit: Just found another door poofed in the nether. 

Doors are not entities (but blocks) and therefore are not covered by this ticket.

Villagers are despawning all the time on our server.  We've also had horses and chickens disappear, but that's not really a big deal. The villagers, however...  grrrrr. 

I see all these bug reports from other people, and that they are marked 'resolved'.  This problem is definitely not resolved.

See MC-153904.

This issue persists in 1.14.4 with villagers disappearing. I see the reference to MC-153904, but it would seem that is a duplicate of this report, which has been discussing villagers, so I’m posting this here.

No, it is not a duplicate of this report. MC-153904 is about villagers disappearing, this ticket is about all kinds of entities disappearing. This issue here has been fixed, only villagers now seem to disappear sometimes.

I have confirmed this issue, or a very similar one still exists in 1.14.4.
I believe it happens to Passengers. When an entity is riding another entity that can walk around.
In this case when these entities stand on chunk borders, are unloaded by the player moving too far away, and then loaded again when the player approaches.

My steps to reproduce this were,
1 Creating a 1.14.4 single player world.
2 Moving out of the spawn chunks to chunks that will unload.
3 using the following command while standing right on a chunk border: 
   'summon chicken ~0 ~0 ~0 {Passengers:[{id:armor_stand}]}'
   in order to summon 5 chickens with armor stands on top of them.

4 teleporting far away before they moved around to let the chunks unload.
5 teleporting to a closeby location and then walking back to the place where i summoned the chickens.

I tested this 4 times and in each case there were several missing armorstands afterwards.
For every armor stand that disappeared I got the following kind of messages in my log:

[18:54:09] [Server thread/WARN]: Wrong location! (64, 21) should be (63, 21), atl['Armour Stand'/36450, l='bug fixing', x=1024.09, y=70.45, z=347.43]
[18:54:09] [Server thread/WARN]: Wrong location! (63, 21) should be (64, 21), atl['Armour Stand'/36455, l='bug fixing', x=1023.91, y=70.45, z=346.25]
[18:54:09] [Server thread/WARN]: Wrong location! (63, 21) should be (64, 21), atl['Armour Stand'/36459, l='bug fixing', x=1023.94, y=70.45, z=341.31]
[18:54:09] [Client thread/WARN]: Received passengers for unknown entity
[18:54:09] [Client thread/WARN]: Received passengers for unknown entity
[18:54:09] [Client thread/WARN]: Received passengers for unknown entity
[18:54:09] [Client thread/WARN]: Received passengers for unknown entity
[18:54:09] [Client thread/WARN]: Received passengers for unknown entity
[18:54:10] [Server thread/WARN]: Fetching packet for removed entity atl['Armour Stand'/36459, l='bug fixing', x=1023.94, y=70.45, z=341.31]
[18:54:10] [Server thread/WARN]: Fetching packet for removed entity atl['Armour Stand'/36455, l='bug fixing', x=1023.91, y=70.45, z=346.25]
[18:54:10] [Client thread/WARN]: Received passengers for unknown entity
[18:54:10] [Server thread/WARN]: Fetching packet for removed entity atl['Armour Stand'/36450, l='bug fixing', x=1024.09, y=70.45, z=347.43]

I attempted this with a few other entities but so far I could only make it happen with armorstands, interestingly, this issue didn't occur when the chicken had NoAI:1, so perhaps it has something to do with the entity moving around?

Remco Schaefer: the issue you describe is tracked at MC-136760.