Hi, I have to deliver footage for a client that will be played on TV broadcast and my exports are looking like garbage with severely jittery frames and compression blocks etc. Check out how bad these are:
Sorry to hear of your troubles. It is said to cut 23.976 in a 29.97 timeline for delivery to 29.97. Pulldown is added, and the footage should play correctly. You have a 59.94 export, however, it should be OK as well, I think.
After reading through your issue a little more carefully, I fear that the issue may have to do with some problem with the M1 Macs. If you have an Intel-based Mac lying around, I would bring the project into that environment and see how it goes. Is that possible? Let me know.