I was flying around using the elytra, and I got sick of it, so I took it off. but, when i hit the ground, i was still in the flying state.
To Recreate:
1. Fly around with the Elytra and use fireworks
2. Hit the ground
3. Take off elytra (optional)
4. If still in a state of flying, you pulled it off
its called the willbur