when going in and out of the nether colormaps sometimes mafunction in a chunk

(this has been tested on 3 worlds which are each split into singleplayer, server and realm)

there is always at least one chunk that "corrupts" its colormaps when i go in or out of the nether and i dont know why

it can easily be fixed with just placing a block or updating the chunk in any way but it can pop up again afterwards

steps to reproduce:

1) make a nether portal and go through it

2) go out while facing either north, east, south or west

3) if you find a strange colormap and it changes back to normal when you place a block that means you have found a affected chunk

note: the realm has been in 1.14 but the server was made in 1.15.1 so it is not that the world is from an old version

note 2: i tested this in a 1.15.2 world and found something interesting. while the bug is still there it came back to the normal colormap automatically after about 1.5 seconds and then i couldnt get it to come back again. i do still kinda count it as a bug though?