Hello Joël, I guess I have a similar setup and had similar lock-ups as your video shows.
I had opened this upstream bug [1]. Either with latest bios updates the situation improved, or last year I started to do after each cold boot another warm boot and have the feeling that way this issue does occur a lot less to not at all. Could you still reproduce this issue - and does it show after a reboot too? Kind regards, Bernhard [1] https://gitlab.freedesktop.org/mesa/mesa/-/issues/1293