AdverseLemon2
Assigned
No issues.
Reported
MCPE-161163
Shulker boxes broken by a piston have weird, unreliable physics
Awaiting Response
MCPE-151535
Inconsistent hopper collection of items pushed on ice by slime block on sticky piston
Confirmed
MCPE-148744
Bells behave as a solid block
Incomplete
MCPE-148009
Controller Sensitivity is VERY Slow
Incomplete
MCPE-146039
Zombies won't attack villagers that are one block higher than them
Incomplete
MCPE-142182
Target blocks visually redirect Redstone dust, but don't actually
Confirmed
MCPE-141533
Waterlogged blocks not converting flowing lava to stone
Duplicate
MCPE-134649
Inconsistent speed for items in a water stream when aligned with anvils
Confirmed
Comments
Just relog and the horse should be back.
The image above is a very simple way to observe this bug. Fill each hopper with a different stack of items and you can watch them transfer from one hopper to the other. Make sure you make one rail a little longer than the other so they will eventually cross with the right timing.
It would be interesting to know what percentage of Java boxes got stuck. Also it's worth noting none of these boxes landed on the piston.