What I expected was: I would not glitch through blocks but be blocked by them

What happened was: Walking/swimming into blocks that are at head height with non-full block/ water beneath, taking suffocation damage, but easily walking back out. If the block beneath the block you glitch into is a block but not full block, you get blocked by the block beneath but is partially in the block above, taking suffocation damage.

Steps to replicate: 

1. Swim in water with elytra equipped.
2. Then walk into block at head height with non-full block such as water, cobblestone walls, or fence gates.

Jumping multiple times makes problem not replicate-able unless you swim in water with elytra again.

 Attached below are 2 different examples.