[Bug] Bad interaction when landing on back on steep slope

[sevmonster]

Describe the bug
Landing on your back on a steep slope that would otherwise make you slide, instead makes you bounce on the slope. If you approach it at the right angle, and there's a wall behind you, you can get stuck bouncing infinitely. Otherwise, you will eventually slow down and start to bounce down the slope. In either case it looks and feels weird, you should immediately start sliding instead.

To Reproduce
Steps to reproduce the behavior:

1. Find an inclined slope
2. Do a backwards dive into it
3. Boing

Expected behavior
Slide, I guess.

Screenshots/Videos

asd.webm

Additional information:

• Game Version: x64
• Game Type: both

Additional context
Non-default cvars:

Beatrun_AnimSet 1
Beatrun_PuristModeForce 1
Beatrun_PuristWallrun 1
Beatrun_QuakeJump 0
Beatrun_QuickturnGround 1
Beatrun_Totsugeki 0