If you put a block in front of a piston and try to push an entity with the piston and the block the piston block will not move the entity, instead the entity will be inside of the block even when there is nothing in the way.

How to Reproduce:

• Get a piston and place it down with any movable block in front of it.
• Place either your player or another mob like entity in front of the block.
• Put a lever in a position to extend the piston and the block in order to move your player or other mob entity.
• Your player/mob will NOT be moved but placed inside of the block that was pushed, when instead the player/mob should have been moved.

Video file Link: https://cdn.discordapp.com/attachments/647554060437815316/705841005454295090/Piston_Bug.mp4