While trying to create a custom biome from the biome "minecraft:the_void", hoping the stone and cobble stone spawn, it didn't.

To achieve this I basically rename the biome config file to my custom biome named and set the custom world to generate with a fixed biome and used this renamed file.

Upon entering the world, no platform were to be found.

I changed the fixed biome to used "minecraft:the_void" and it worked.

So I tried copying the overworld dimension setting from a newly created superflat with "The Void" preset. I checked it would work (and did so).

Then I switch back to my datapack custom biome (which is a renamed "the_void.json" file), but it wouldn't work once again.

I have attached my datapack in case the problem is a datapack related problem and not an actual bug.