When pushing a water logged block with a piston, it removed the water from the block.
Linked issues
is duplicated by 9
MCPE-71820
Water logged blocks can no longer be moved by pistons
Resolved
MCPE-72570
Slab and Water Bug
Resolved
MCPE-83296
Water logged bug
Resolved
MCPE-86166
Waterlogged Stairs Pushed or Pulled by a Sticky Piston No Longer Stay Waterlogged
Resolved
MCPE-86254
water disappears fro waterlogged blocks when they are moved
Resolved
4 more links
As a Parity Update for v.1.16.0.51 - Beta Blocks will now lose their waterlogged state when pushed by a piston, reference here:
https://feedback.minecraft.net/hc/en-us/articles/360040975731-Minecraft-Beta-1-16-0-51-Xbox-One-Windows-10-Android-
Fixes and Changes
Parity