This Bug also occurs at Beta 1.16.0.53. When so much mobs(ex: m
zombie) Is placed in a 1x1 area with a non solid block(ex: slabs) will spat out the baby 2 block hig mobs are spawned much will make them fly out the container. Whereas if you extend and retract a piston with a redstone clock (any kind that is fast) will make mobs fly out of the space (like the translocation bug that was in java but uses many entities