AE Mac Intel render bug alpha when shown on M1

Rendering a AE comp 9×16 ProRes 4444 with alpha on Intel Mac. Looks fine on the Intel Mac.

Bring the file into M1 Studio and there is a vertical black line in the alpha channel that shouldn’t be there. (Render that same AE comp on an M1 and the line is not there.)

Is not a problem with 16×9.

It does appear to be a bug.

(bug report https://developer.apple.com/forums/thread/694622 FB9909638 on Apple developer forum — something about 64AERGB on Intel and 64RGBALE on Apple Silicon. Beyond my pay grade on what that means.)

I can take that same ProRes 4444 file and bring it in to AE M1 and render out a simple 4444 comp of it and it goes away.