Wurst version: v7.47 (also in v7.46.6)
Minecraft version: MC1.21.4
Steps to reproduce:
1. Activate NoFall & Flight
2. Fly Forward
3. Start crouching while flying
As soon as you start crouching while flying to get lower, youll be gltiching back and forth, but ultimately staying in the same spot.
Edit: More or less optional, but you need to be in Survival, so the NoFall wont be paused. Forgot to mention that in the aboveā¦