Weird youtube fullscreen mode

Steps to reproduce:
visit youtube.com
play any video
enter fullscreen mode

Expected behavior:
no white bar at bottom

Orion, OS version; hardware type:
Version 0.99.121-beta (WebKit 614.1.20)
Macbook-Pro(M1 pro)

Image/Video:

1VbBoIlR9XB3dFKh Hm not able to reproduce.

Vlad fixed, Version 0.99.122-beta