@Cyclonit
613f0fa seems to be the cause of this issue.

There are significant chunk loading issues when using optimised cube loading.
The ChunkHolder is not set at all (always null), nothing is loading for the affected columns.
Moving to a new area will start generation in that new area.

This was fixed, but I can't for the life of me remember of find the commit that did.
It was due to a duplicate method somewhere.

Turns out the issue persists: https://hatebin.com/zvngjroeru