Datapacks which change worldgen settings sometimes stop working from version to version
MC-224411
Datapack compatability
Resolved
Awaiting Response
0
The worldgen datapack from 21w15a will not work on new versions. You need to use the updated version provided in the 20w17a change log: https://www.minecraft.net/en-us/article/minecraft-snapshot-21w17a.
If this isn't what you're talking about, please provide more information about your issue.