I do not have any pictures at the moment but it has happened a few times within the last few weeks.

Randomly in the dedicated server random chunks usually 16x16 or 32x16 will be replaced with fresh ones, sometimes resulting in a massive hole to the void as well along-side a new chunk.

For example; In my nether within a fortress the entire fortress for a 16x16x256 hole appeared deleting a perfect square, same happened in the overworld near a bridge I made and within a building I made too requiring us to fix it manually.

It seems to be a chunk error/failure to load/regeneration bug?

Any info on how to fix this?
I have moved the BDS to an SSD for testing

EDIT: I have also seen a few chunk/void errors appear when typing "Stop" into the cmd. I have started kicking all players before reboots to minimise the chances but it still happens sometimes.