Entities fall through Shulker Boxes when opened and pushed against a block

Shulkerboxes pushes Armorstands up and pull it down again, when you open them quickly. If you open then longer the armor stand glitches in the shulkerbox falling down. When a player is standing over the shulker box there must be a block above to reproduce the bug.
16w40a: Only glitches if the shulker block pushes a player, armorstand, etc... against a block.