Minecraft version: 1.20.1
DH version: 2.0.4-a-dev
Oculus version: 1.7.0
Bliss-Shader version: latest in-development
The sky fills up with whatever is on the floor, whenever I turn off DH LOD rendering it fixes.

this is a super common issue related to iris
there are a few ways to get around it.
restart the game this is just DH crashing. if restarting does not fix it go to Distant horizons settings -> advanced options -> graphics -> rendering -> change transparency to complete

It was always set to complete

well, then... i am unsure how to fix this. you'll have to talk to the iris people, or distant horizons people directly

Turns out it was an issue with Alex's caves which had been reported before AlexModGuy/AlexsCaves#519