_ThePureVessel_

It only occurs on lower end devices and is most attributed to network issues rendering the chunk in. All devices are affected on mineplex, so that's not completely it. Try upgrading your device or improving your network

This does not occur/cannot replicate. This is most likely an internal issue within your device rather than the game.

Try using windowed mode rather that fullscreen

This bug most often occurs within the java version of the system but it depends on your CPU and GPU. If they are old and this is a newly occurring issue, it is due to failure of them. Otherwise there might be failing code or corrupted code. Usage of hacked clients most often leads to corrupted internal processing code.

Do not worry of bugs, this is one of the things the anticheat does for speed/alwayssprint cheats

That seems like a internal issue within your device and not the game because I cannot replicate even on multiple platforms

Old style worlds can still be imported into the game and some maps use old-style world

This may be an error within your own game. Have you tried uninstalling and reinstalling? This may be on your devices end and not minecraft's.

I Cannot provide screenshots or videos.
Try to replicate this bug on your own.
Example: spawn the wither inside some blocks while in spectator mode, the wither will take damage and move up to an air pocket or make its own, if mobgreifing is enabled.
non-flying mobs will gain free movement except for down.

Ah, I see your issue!
The site thinks that someone owns that tag, therefore you cannot use that tag.

I had a similar issue, that is why you see underscores before and after my tag.
I hope this helped 🙂

Note: add or remove something from the tag and it will be valid.