I experience this too, I also reported it. I play bedrock and this problem occurs. Although the block does +NOT + need to be netherrack, it can be any block
Correction, Its not only Netherrack, its with all blocks. If you place fire ontop of any block, then destroy the block under the fire, it is invisible
I experience this too, I also reported it. I play bedrock and this problem occurs. Although the block does +NOT + need to be netherrack, it can be any block