When waterlogged blocks such as fences, slabs, stairs and trapdoors are either pushed or pulled by a piston, the water source block disappears.
Is unaffected by whether or not it is directly connected to a piston or through slime block(s).
When waterlogged blocks such as fences, slabs, stairs and trapdoors are either pushed or pulled by a piston, the water source block disappears.
Is unaffected by whether or not it is directly connected to a piston or through slime block(s).
Chaomatic
(Unassigned)
Unconfirmed
Minecraft 1.13
Retrieved
This is normal, it is to avoid the grief on servers it seems to me.