I have done further research on this issue, and I have found that almost any time that the player is pushed into a block(pistons, standing on shulkers, gravity blocks) will activate this bug. I have noticed that it somewhat halves your hitbox to about 1 meter tall, but the suffocation box is still at the correct place.
That is a blessing, not a bug.
Do not resolve the problem.
Please.
Thank you.
😃
This issue is also present on the most recent release for xbox one.