Retracting pistons push entities which are directly behind the piston base back a little bit, this can be seen in Recording #1.mp4. As the entity is not visibly intersecting with the retracting piston, there should be no reason why the entity is moved.
- Place for example a sideways facing piston
- Stand directly behind the piston base
- Power and unpower the piston
→ You should be pushed by the piston