Sequence settings: 1920×1080, 23.976fps, 48000 Hz Stereo
All clip settings are the same
Export Settings: 1280×720, 23.976fps, 48000 Hz Stereo
Everything is matched except for the frame size, I’m fairly sure it has something to do with the final QT H.246 file, but why I just don’t know. Quite frustrating.
Cheers