Trapdoors on the ground closing while crouching under a slab has weird behavior

Oddly when crouching in java edition with a opened (on ground) trapdoor with a top slab (above) then closing the trapdoor bellow, your character goes into the standing model and being able to move at walking speed, however your player camera is still in the crouching position (this also applies with the players hitbox).

 

What I thought to expect was entering the crawling animation/hitbox as there is no more space for crouching. Although it seems it did the opposite.

 

Normal behavior

How to reproduce

Odd Behavior