The bug

If we place a partially rotated skull or head, and look at its hitbox, we see that depending on the viewing angle, its hitbox disappears partially. It doesn't matter if you use "Fast", "Fancy", or "Fabulous!" graphics settings.

Look at the attached images to clarify.

To reproduce

1. Place a skull/head (not the Dragon head) rotated on the floor
2. Look at its hitbox disappear depending on the viewing angle

In 1.15.2 this was not the case.