Sara Jarvis

Yes this is still an issue. It is particularly bad during the auto saves.

This glitch will allow you the player to glitch through blocks and see underground structures such as mine shafts while surface mining. It happens due to the delay in which you've mined a block and when the game updates to reflect the block was mined.

This is still an ongoing issue. Due to the limitations of the Nintendo Switch I can not upload a clip of what happens. The animation issue seem to be caused by the game system after autosaves. Autosaves temporarily stop animations and the system will suddenly update after the process has finished. It causes animals, blocks, even sound to be delayed.

I am on a Nintendo Switch and can't upload a world. So any help from others having this issue would be much appreciated.

I've mapped my animal pens with torches just to keep things straight using @Etanarvazac 's suggestion. I'll continue to check and see if the animals stop disappearing altogether now that I've fenced them in such a way as they can't cross any chunk borders. I have left 2 small mine carts running across the chunk borders to see what if anything may occur there.

It's more difficult because unlike the Java version you can't just pop open a visual grid display on the fly and must use math to find and remember the multiples of 16. 

I have been testing further on the Switch and moving things around on my house area. Keeping animals in smaller pens with only 3 to 4 blocks of movement in either direction has reduced the number of times they disappear. Culling the growing Wandering Trader llama pack in the cave under my house has also reduced the number of penned animals disappearing. Every time the Trader moves across the chunk border he leaves behind his llamas. So I have to cull them frequently but at least I now know why I found so many of his llamas and where he went. I moved where I was placing armor stands and they have stopped disappearing. So I may have placed my house across a chunk border without knowing. It's hard to tell on a Nintendo Switch. Anything that reduces the strain on the memory and processor reduces the amount of unwanted culling of fenced mobs. 

Acting more like the memory is being throttled or capped in some way causing fenced mobs and such to be dropped like free mobs are cleared as part of how the game operates. The heavier the processor and memory are used the worse it starts clearing entities. It's just some of those entities I wanted to stay. Fenced, in a house, no where is safe from the cleaning. There is one mob that is populating when things start going missing and it's the wandering trader llamas. No trader just the llamas. I've got half a dozen in the cave under my house and the minute I see new ones I know something at my house has gone poof.

I'm playing a single-player world on a Switch and having these issues. The game is behaving as if it were clearing untouched naturally spawned mobs in a newly unloaded chunk but it's not just clearing untouched mobs. The biggest commonality I can find is that to some extent we all use some amount of cloud-based computing/saving. I see an uptick in issues when autosaving and/or the game is using this cloud service heavily. The game is doing what it is designed to do to save memory and computing speed just with the wrong mobs and such. I can't decide if 1. it's a coding issue (Being mobs are not the only casualty I'm less sure of this one. Unless armor stands are a mob?), 2. the cloud is shedding because it is getting overloaded in some way, or 3. some combo of 1 and 2.

I am working on my end to produce a better bug report according to the guidelines. The frustrating aspect of this bug is that there are not always a consistent set of steps to recreate this bug. I am still working with my Nintendo Switch so I am limited in other respects as to what evidence I can share. Please bear with me. I am working as best and as fast as possible. The issue seems to lie within how the game's memory system works. The most consistent results I'm getting at this time are as follows. When I leave my home chunk to gather resources or whatever for anything over about 10 minutes and then return to my home chunk naturally spawned mobs and some and/or all of my fenced mobs etc. may have been purged. It does not occur every time but I have noticed if I've been out doing a lot or picking up a lot of items it happens more frequently. As to when it happens after I've saved and exited or had the communication error I have not been able to get as often. It seems to occur at these times if I've interrupted the game during an autosave. Either way what I have not been able to determine is if there is a communication interruption going on with the memory or if the Switch's memory limitations are being overloaded possibly too much info all at once and/or trying to save as much space as possible. I apologize I haven't been as quick or as neat with my reporting but I'm doing my best to gather the info you need. Thanks for your understanding and hard work team.

It does not give me an error code when the communication error occurs. I've been paying vanilla the only marketplace content might be my character's clothes. If you leave your game running but unattended too long it will trigger a communication error or if the internet goes down. No idea why leaving it set does this either because nothing happened to my internet while I let it sit and it only happens in Minecraft. I've left other games running and it doesn't disconnect from the internet. When it errors out the game doesn't crash and appears like you can still play but if you save and exit it may or may not have saved correctly and that's when the mobs go poof. As a side note the marketplace and dressing room on the Switch is rough and doesn't load correctly since I've owned it. They have massive loading issues.

Upon further testing chunk loading and unloading seems to be the biggest culprit of missing mobs. The only time I lose mobs while saving and exiting is when the game loses communication and gives the communication error message.

I've added a screenshot of the main menu page which just updated to 1.18.11

As I don't know what this update changed yet I am happy to retest everything.

I am running the latest version of Minecraft. I tried adding animals in pens to an existing world after the update. They disappeared after I saved and exited. I then tried making a new world and putting animals into pens I then left my home area chunk and the animals were gone when I returned. This could very well be an issue that is Nintendo Switch unique. 

I too am still having this frustrating issue. Do I need to put in a separate ticket?

The glitchy movement happens regardless of if I'm on Wi-Fi or not. It happens regardless of if I'm on multiplayer or not. The last few updates have lessened the issue on my LG G6 but it has not gone away.