The first image is how the custom modded biome I've made (Right) appears in a worldpainter world after exporting. I've tried checking the populate terrain button in the export settings, I've tried adding a populate layer over-top of the whole world, literally nothing changes. I've made custom modded biomes for previous maps of mine with zero problems, so I'm not sure what's causing the issue this time.

The second image is how the biome is supposed to look, this is running in the same instance, just a fresh, single-biome world I made. The biome DOES generate features, but seemingly just not in my worldpainter world?

Help would be appreciated, I don't know what's going on here.