Export errors and Glitchiness OS 12.3.1/ FCP 10.6.1

I have been having issues ever since moving to an M1 Max MBP in January. All exports end up looking like this image. And today suddenly my project seems to have corrupted and now my footage in the timeline plays back with these same looking frames intermingled throughout. Notice the weird "Mark" text at the top. Where is this coming from?? I am attempting to transcode all footage from a 1-hour shoot to see if that makes any difference. And yes I've rebooted, dumped preferences etc, but to no avail.

I should note that in order to use FCP with Monterrey I have to operate using the Rosetta version so my plugins still work. I can't confirm if this is the cause of the issue, but I certainly can imagine it could be.

Does anyone have any thoughts?