I am not a dev, but a video Postproduction operator. I use prores4444 with alpha all the time. Works all on my intel iMac. But on my new M1 max MacBook Pro some files are shown black with glitches, not correct with alpha channel. I posted a bug report. FB9909638

Damn. Right now, this machine is totally useless for me - I can't edit my current project on this machine. Come on Apple, this is a totally serious issue - fix it now! I will return the MacBook to Apple until the bug is solved. Good luck everyone!