MemoGoodNameYes

This happened to me (as the host) after changing the world to Friends of Friends from invite only - it's a creative world and I have a play timer on a scoreboard so I could see I had been added as a totally new player (now showing as "Player Offline").

Upon restarting the world I was back to normal, but the "Player Offline" that was created is still there.

Edit: I joined someone else's multiplayer world to try and troubleshoot multiplayer issues I was having, and when rejoining my creative world I was back as the totally new player (the same one). Leaving and rejoining put me back to normal again.

Edit 2: Every time I join someone else's world the first time I join any world I'm there as If I'm a new player. This may help with recreating the bug

1. No tools used on any.
2. World has not been on a realm.
3. This has happened on 15+ worlds for me - all (as far as I remember) last loaded 2017 or earlier.
4. No. Don't believe ticking areas were around that early.

Possibly related to MCPE-85039, MCPE-87376, and MCPE-87503 which are related to chunks that haven't been loaded in a long time.

Harming potions don't give a status effect - they just do damage. So if a witch threw a harming potion no effect would appear.

The biggest issue I personally see with it is that it could easily be used by players with creative mode access to grief things quickly, and to create explosions when these have otherwise been intentionally turned off. If this isn't a bug, maybe a gamerule could be added?

I still think this is likely a bug however.

It feels similar for me. I think the input delay might have increased. No way to measure it though so I'm not sure if it has increased or not

on the side note said by madegeeky, this issue was seen in the beta versions as early as september, but not in the actual game until a release in the last few days.

I tried changing from the Nvidia GPU to the Intel one, but for me that didn't solve the problem. Frame rate was noticably worse (but that was expected), however there was still bad input lag.

Alfred Osborne's comment fixed it completely for me (nvid 1060). Obviously not ideal playing w/o smooth lighting etc but it's playable now.

I also did notice (before fixing it) that the mouse input lag also exists when the mouse is in its normal mode (e.g on the worlds menu/ in the settings).

This is definitely something to do with rendering. I updated all my drivers. I have Intel UHD Graphics 630 and NVIDIA GeForce GTX 1060 and 16gb ram.
Been playing on console instead, which doesn't seem to have this problem. Hopefully this is fixed soon.

I uploaded a file that shows where the invisible chunks are. Everything past the red line can be entered, and there's water particles there, but it doesn't appear visible.

I attached a .zip file containing the world. Some parts of the world are full entirely of invisible blocks, and the world crashes. It isn't the exact world I used earlier, but exhibits the same behavior.

Temporary fix (but mojang should still fix this)

Load the world in MCC Tool Chest PE.
Convert the world to Java edition,
Load the world in java (although you may not need to do this)
Convert back to bedrock

Save as a new world file

Should fix the corruption issue

This would have pretty major ramifications for griefing though, wouldn't it?

If I had to guess, I'd say it has something to do with the air being in either corner. The villager might think they're already indoors.

Unable to verify
Uploaded renaming.png

More information at MCPE-87376

Similar to MCPE-85039 but with more information

Managed to recreate the 2014 world bug on Android phone, including the crash when trying to make the world infinite.

Do you have enough storage?