I was only able to add 1.16.1, (not sure what versions it's in)
Reproduce:
Create flat platform of waterlogged top-slabs & trapdoors (maybe other blocks, haven't tested)
Spawn creeper in, or blow up TNT and skip 3 & 4
Go into survival
Let creeper blow up
Waterlogged blocks act like water blocks, this is intended and always has been.