Ok so when I was on Minecraft I noticed that when I went through a door quickly then jumped, my bubble bar appeared. 

How to reproduce:

1. /give @s door
2. /give @s stone_slab
3. /give @s stone
4. Place the door, and put a stone block on top of it. 
5. Put the stone slab on the side of the door that is not the front. (top half)
6. Open the door, move quickly through it, jump as soon as you have gone through the door then close it. 

Expected results: Your bubble bar doesn’t appear.

Observed results: Your bubble bar appears for a short amount of time. 

Note: If you are finding this bug hard to reproduce, look at the video. Sorry about the poor video quality.