I don't really know if this is a bug or if this is intended but it's a shame that it isn't possible to play with the new Nether biomes and the modded ones at the same time, it would be so cool. Currently, only the 3 modded biomes you added are generating so 90% of the content that was implemented in the Nether update is basically inaccessible in survival.

Mod version: 1.0.5

Patched: https://www.curseforge.com/minecraft/mc-mods/oh-the-biomes-youll-go-fabric/files/3001588

Lmk if it works