Opening a shulker box while an entity is standing on top of it pushes it too high for a short amount of time

The bug

When you or another entity is standing on top of a shulker box and you open it, the entity will be pushed a little bit too high and then it moves back down. This didn't happen in 1.16.5. Apparently you get pushed up by 1.01 blocks instead of 0.51, how it used to be in 1.16.5 and then you will fall down. This can easily be noticed by flying above a shulker box in creative mode and opening it.

How to reproduce

1. Place a shulker box facing up
2. Stand on it
3. Open it
   → You will be pushed a little bit too high and then you will go back down again