What happened?

BClib doesn't seem to be generating vanilla biomes correctly, and sometimes even modded biomes don't generate correctly (including betternether's Old Warped Woods).

Soul-Sand Valley:

Crimson Forest:

(Old)Warped Forest:

Warped Forest:

Fungi Woods:

Bone Reef:

Gravel Desert:

Soul Plain:

Mod List:

BCLib

bclib-3.0.14.jar

Fabric API

fabric-api-0.92.1+1.20.1.jar

Fabric Loader

0.15.6

Minecraft

1.20.1

Relevant log output

https://pastebin.com/pHQarzF9

I can confirm this is caused by Regions Unexplored and BCLib conflicting somehow