Chunks go missing where any element of the mod resided.
I know this was an RC, but thought worth mentioning in case it was missed and went live corrupting worlds.
(I have many backups 😄 )

This was tested on
MC 1.18
Fabric Loader 0.12.8
Fabric API 0.44.0

I went though my list of mods testing the cause of this, as soon as TSS was added this occurred, so I am in no doubt this mod causes it.

thanks for resolving :)