Version
1.16.5

Modloader
Forge 1.16.5

Describe the bug
All the Biome IDs have changed around, I am unsure of what happened or how to fix it but what should be a normal overworld biome has now turned into the Subzero Hypogeal biome from the nether, ghasts have begun spawning above my house, which is very unpleasant :(

To Reproduce
Please provide step by step instructions
Unsure of how to reproduce, I have upped the spawn weight for biomes in the configs but as far as I'm aware there is nowhere to change BYG IDs so no clue how it happened

**Screenshot

Did you remove any mods that add biomes/dimensions? Biome shifting happens to me as well. It can also happen if a mod changes their ids during an update. I highly recommend https://www.curseforge.com/minecraft/mc-mods/biome-id-fixer

what @Yourname942 said. This is a vanilla issue, upvote the biome shuffling bug: https://bugs.mojang.com/browse/MC-202036