The basalt delta generation looks like the wasteland generation. In the snapshot, I saw

• MC-198129 - ReplaceBlobsFeature changed from 1.16.1 to 1.16.2, affecting Basalt Delta generation

I'm not sure if this may be the cause or if its purposeful. I couldn't find any other support saying thats how its supposed to be.

For some reason, it kept erroring out to upload the picture, so here is a link: https://ibb.co/pnH6vNX