USB Superdrive playing DVD's off-centre when full screen on 2020 Macbook air

I have been using the USB superdrive to play DVD's on this Macbook Air for a year without issue. It is connected to the USB-C with an official Apple adapter.

I updated my OS to Tahoe 26.0.1, and since then, fullscreen DVD's have sliced off around a sixth of the picture on the right hand of the screen, and the controls menu for the DVD player also appears off-centre.

I have tinkered with screen resolution in the "Displays" menu, which results in different amounts of the picture being cut off, but never a centering of the picture in frame. Nothing in the DVD player toolbar menu helped.

It may not be related to the Tahoe update, but there was a definite before/after! if anyone has ideas, do let me know.