Bees inside of bee hives / nests sometimes despawn when the world is reloaded

ive noticed other entities disappearing other than bees since 1.17. 4 villagers and a zombie that i had on a track  way up off the ground for an iron farm. 

This bug continues, my bees despawn slowly but constatly, now i have another time 0 bees from 90, in all 1.16 updates bees are working good, i dont know what hapens , is like when i use de dispenser whit the scisors bees inside de bee hive despawn, it could be.

this has been happening for a while, since 1.16 maybe, i have them closed too on a honey farm and they end dissapearing all the time, it seems that has to be with the distance with the player or something or the dispenser too who knows, but it bugs me cuz i had like 40 bee nest and they arent specially easy to find/farm.

In 1.17.1 this bug continues, another time i had have to put bees on creative mode.

Can confirm, bees randomly despawn without explanation

It seems that this issue is caused by entities not being stored with chunks anymore. When entering a hive, the BeehiveBlockEntity#addOccupantWithPresetTicks method first stores the bee and then discards the entity. In 1.16, discarding the entity marks the chunk as unsaved. However, in 1.17, this does not happen. In order to fix the issue, this code needs to also call BlockEntity#setChanged, to ensure that the chunk is saved again so that the entity stored in the beehive is not lost.

TLDR: add this line somewhere inside BeehiveBlockEntity#addOccupantWithPresetTicks to make sure the bees are saved.

this.setChanged();

I also had the problem of bees completely disappearing in 1.17, and it just happened again sometime after I updated my game to 1.17.1. I had bees completely enclosed in a completely closed-off and well lit area, and all my campfires were enclosed in solid blocks and covered with carpets to make sure the bees didn't take damage on them.

But still, they just disappeared all at once. I already had to repopulate the beehives twice, and it just happened for the second time.

Yup I've got a honey auto farm with 4 nests with multiple bees in each and it was running smoothly for a few days.  I could hear and read that the dispensers were firing then noticed today they were quiet.  Went over and not even a 'bee is working' text.

It happened to me a third time. I had even nametagged all my new bees, but they still despawned! That's just unacceptable, especially since honeycomb became so important in 1.17... please Mojang, fix this!!!

Happens to me as well, noticed it with the last few worlds i created in 1.17.1, create honey farms and then at some point all the bees vanish, so i re-populate the hives/nests and then again at some point they vanish again, and have to rinse and repeat.
Thankfully haven't noticed it happen with other mobs, just bees.
Never had bees disappear in any of the 1.16 versions

I had commented on MC-228937 about this, but they're closing that as a duplicate of this.

I've had bees disappear since 1.17

A weird issue I have right now, is that I built a set of enclosed hives as a farm to keep them safe, but they won't come out.

The hives are buzzing, so the bees don't seem to have all vanished this time, but no bees popping out.

Has anyone else got any of their hives making buzzing noises despite no bees appearing?

I definitely have had a major issue with bees just vanishing, so I definitely have this bug, I'm just wondering if the concurrent bug of them being stuck in hives is something I should be setting up a different report for?

I think it could be bees damage against stairs and upside down stairs, some bees death on my server but we have spigot plugin, maybe the plugin is wrong, but in my own single world i need to prove if stairs kill bees by sufocation.

I don't have any stairs or blocks near the hives for them to suffocate on, or anything in the farm that could cause them any damage and cause them to die.
It's surrounded by glass and only the front of the hives are exposed to the farm, so they are just despawning, not dying from damage etc.
Seems to be similar to the bedrock issue where passive mobs can despawn, but with Java it just seems to be bees that are affected, as i haven't seen any of my other animals or villagers etc despawn.
Oyuyu, i've had that happen once or twice, bees get stuck in the hives/nests and don't come out, despite nothing blocking the front of them, i ended up just restarting minecraft and they came out of the hives if i remember correctly.

I've had the same problem on a server me and my friends were on, but one of my friends noticed something. They managed to silk touch the natural bee nests and made a greenhouse with the nests inside of them. And as of yet, the bees haven't despawned in the enclosed space. I wonder if it's a problem with the crafted beehives as opposed to the bee nests. Thoughts?

I happens with both, i've had nests and hives (most recently hives), but i've had them despawn with both.
Sometimes they will despawn quickly (in this case it was maybe a few days after creating the honey farm), but in other cases it can take a lot longer, it seems to vary

Could not replicate on 21w44a

All of my hives are silk touched.

I have no stairs.

Gavin - this is all the time since I built the farm. I've logged out and in lots of times since then and they're still buzzing with no bees.

I'm talking about bedrock, I hope I haven't been redirected to a java bug.

Edit: I have. This was the bug report we were sent to from a java bug. So my issues don't apply sorry.

This is a java report Oyoyu, I was simply stating i could not replicate this issue in 21w44a

Well, like i said before, i've had them disappear quickly, and other times it's taken a long time (IE: playing for weeks without them despawning), so it seems to vary

Hopefully, as Dylan can't replicate on the snapshot, the issue has been fixed for you in Java going forward.

Mojang staff: How do I get a bug reopened? I was commenting on a bedrock bug, and it was closed as a duplicate of this bug, and I naively assumed we'd been sent to another bedrock bug.

Is there actually the chance that a fix will be applied to both? I thought the whole point of separate bug report areas was because the code is different, so bugs will be, on the whole different, and for different reasons.

For anyone else coming here from the bedrock bug, just be aware this is a java bug report.

To the people commenting here - sorry; I'm rather worried that my bug issues won't be the same as yours, as I'm on Bedrock, and that my info may have confused any searching for the bug.

Lost lost my pet because of this!

This still seems to be a problem for 1.18-pre6. I really hope this is fixed before 1.18 releases. Having mobs despawn like this is extremely irritating. (I'm making a small video showcasing this bug report)

I made this tiny video showing how to reproduce this bug and some temporary solutions to it.
https://www.youtube.com/watch?v=r2b3L2HzjyY

I hope this can confirm the issue

Feel free to include this in the issue. This would be amazing to have fixed.

This bug is still apparent in 1.18 rc-1

Can confirm in 1.17.1, snapshot 1.18 pre 6,8. Also in 1.18 rc-1.

Thanks to Antho Foxo for posting the workaround.  It turned out that all of my hives and nests were in one chunk, and adding a single (hidden underground) hopper clock fixed the despawning issue.

Sounds like basically they need to make it so when a bee enters/exits a hive/nest it will force a chunk update

Can confirm for

1.18-rc1
1.18-pre8
1.18-pre7
1.18-pre6
1.18-pre5
1.18-pre4
1.18-pre3
1.18-pre2
1.18-pre1

The only case I have been able to reliably observe this bug is when I restart my server while they are in their nests. Bees outside of nests don't seem to despawn so as mentioned before it might have something to do with nests/hives not getting saved correctly. I tested this in 1.18.

On another note: If you have an enclosure with one-block walls and ceiling, lightning seems to be able to kill bees through the ceiling/walls so I would put a lightning rod somewhere a few blocks away. This is something that could also lead to bees disappearing (intentionally I suppose) but they definitely also disappear without any reason.

Although lightning is a possibility for some bees disappearing, i've had honey farms down near bedrock level, without any sky access, so no way for lightning to get anywhere near them.
All i can suggest to people (for now), is breed a lot more bees than you need, and keep some nests/hives spare to replace any you lose, until it's fixed

If you just put a hopper clock in the same chunk as your bee hives, this will fix the issue until the bug is handled

Bug still occurs on 1.18.1-pre1

This is occurring for me on a personal realm as well, a fix before 1.18-pre1 would be greatly appreciated

I'm having bees disappear on a vanilla 1.18 server, F.

I'd like to add that my bees have de-spawned as well, both in 1.17.1 and 1.18. My Bee enclosure is in my spawn chunk and its happened twice.  I've also made sure hives are not blocked by vines or carpets.

im in the 1.18.1 pre. my bee disapper inside the hive in a chest!!!!! (i lost like 2 doble chest full of hive with a least 3 bees per hive), and if i put an empty hive and take it back the game show me the tag like the hive have a bee.

I've adjusted the title of this bug report to reflect what we currently know about the issue: most disappearances of bees appear to be linked to the fact that the bees have bee hives / nests near them that they can jump into.

@unknown your issue seems to be different, please file a new bug report about that.

I changed the stairs i was using in bee farm for block and it look like bees does not despawn now, it could be the stairs problem. I dont know.

It seems to have been resolved in 1.18.1-rc1, but there were comments saying it was still reproducible, so I tested it.
Can't reproduce in 1.18.1-rc3.

Still happening despite supposedly being patched, bees disappeared completely on realm world, in 1.18.1

I friend and I also keep having this problem on java in 1.18.1.

My bees have been despawning in 1.18(.1) as well. They're in an enclosed space, with no campfires to begin with. Both nests, and hives are present. The crafted hives are embedded in a wall, with the door pointed outwards. I do have them all auto-sheared. 

same on my side problem is all my animals are gone I got some pretty rare ones and I just logged back in to find that my frowning faced panda is gone!

I am hating this

and my axolotls are also gone

1.18 vanilla realm, just finished a 64 hive honey farm in the end. Bees weren't despawning, I could hear them. Tried a few things, but looks like the bees are working after I fully closed and re-opened the realm. Hope this helps someone.

Can confirm, this is still happening on Java 1.18.1. Vanilla, no resource packs. 

I've tested this in an enclosed chamber with the be hives directly next to each other. Still happening. 
I made a 1 block air gap between the hives and it still happens.
I made a 3 block air gap between the hives and it still happens.
I placed a grid of bee hives in an open, flat field. Each bee hive was 3 blocks from each other and 3 blocks from the ground. I covered the ground with flowers. The bees still disappear.

Yeah, sorry but it's still happening.

All code analysis in this comment is done in (MojMap 1.18.1)

Yes, this still happens in 1.18.1 and the reason is pretty simple.
As mentioned in https://bugs.mojang.com/browse/MC-229321?focusedCommentId=1061634&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-1061634 the chunk was not being saved which is why the entities disappear. Although the bug was actually caused by 2 factors. The one beeing about chunks not saving (just mentioned), and secondly the chunk which the bee entity checks for block entities might not be loaded.

Let's beegin with the first problem (which was solved in 1.18.1) Basically when the bee entity would enter the hive, the beehive block entity would not tell the chunk that it needs to be saved. The fix to this is simply adding:

super.setChanged();

Where relevant inside BeehiveBlockEntity.java, which you did in 1.18.1!

The second issue is the chunk that the bee entity checks for block entities might not bee loaded. Since the bee gets the block entity through the PoiManager, which never unloads chunks thanks to https://bugs.mojang.com/browse/MC-173001.
This could be an issue since that would mean all changes to the block entity do not matter, and the extra checks you added did nothing.

Now for the fun parts. You are probably wondering why super.setChanged(); does not... or maybe you didn't notice it yet. Let's look at its code:
BlockEntity.java

protected static void setChanged(Level level, BlockPos pos, BlockState state) {
    level.blockEntityChanged(pos);
    ...
}

Level.java

public void blockEntityChanged(BlockPos pos) {
    if (this.hasChunkAt(pos)) {
        this.getChunkAt(pos).setUnsaved(true);
    }
}

As you can see, it checks if the chunk is loaded. If the chunk is not loaded, it doesn't even save the changes. That check is there, beecause it's possible to have the block entities not bee in a loaded chunk.

The solution, add checks to make sure that the block entities are within loaded chunks, simple.
Carpet-Fixes already does this in bees here and hives here

This text editor is going to be the end of me...