Skeleton displayed in the Trial Spawner can get out of the Spawner a bit

Steps to Reproduce:

Look at top of a Skeleton Trial Spawner.

Observed Result:

Skeleton displayed in the Trial Spawner can get out of the Spawner a bit. [Can compare to Bogged(Bogged will display correctly)]

Expected Result:

Skeleton displayed in the Trial Spawner won't get out of the Spawner.