Some biomes roof has netherrack  instead the biome specfic blocks for those biomes. Such as

Soul sand valley, Basalt deltas 

See comparison from bedrock to Java

Unfortunately, The website won't allow me to put the picture for this problem

To repeat this bug go to theses biomes on both platforms

Java and Bedrock and look at those roof of it. And you see what I mean

PLEASE FIXX