Huge red/brown mushrooms can't grow in/into water unlike other fungi and trees

modded imgur video: https://imgur.com/a/ebztqxF

vanilla 1.20.6 video: https://imgur.com/a/zBdZODD

Both nether fungi types and all saplings can grow in/into water blocks when bonemealed but red/brown huge mushrooms cannot. 

Expected behavior: red/brown should be allowed to grow underwater to be consistent with the nether fungi and other saplings.