Clipping through blocks in creative mode

Steps to Reproduce:

1. Enable the Short Sneak experiment;
2. Create a ceiling hovering 3 blocks off the ground;
3. In creative mode, crouch and then double jump into fly mode.

Observed Results:
You stop crouching once you enter fly mode, which causes your collision to clip through the ceiling due to the jump height being slightly higher than a block.

Expected Results:
Your collision remains the same, preventing you from clipping through the ceiling.

Screenshots/Videos attached: Yes

Notes: