Minecraft 1.20.1
Forge 47.1.47
Apothosis 7.0.5

Seems to be some sort of issue with structure generation based on location. It varies but can be random. Reason I bring this up is because the structures are generating in strange places and just look out of place with floating islands under them.

Can be recreated on any MC world with the Apotheosis mod included

Think the biome tags need to be made more granular.