Flying into water with an elytra and swimming backwards flips your character upside down

What I expected to happen was...:
Normal fast swimming. (Swimming backwards cancels the 'fast swim')

What actually happened was...:
My character flipped upside down when swimming backwards

Steps to Reproduce:
1. Fly with elytra
2. Steer towards the water going under the surface
3. While fast swimming, move backwards
4. Go into 3rd person and you will see that your character is upside down (see screenshots)