When a cauldron filled with a liquid is pushed/pulled by a piston, the liquid appears to be water during the movement. This did not occur in 18.104.22.168 and earlier. Back then, there was a different bug:
MCPE-16452, which has now been replaced by this one.
- Fill a cauldron with a potion to any level.
- Push the cauldron using a piston.
- Notice that the liquid looks like water momentarily while being pushed.