MOV file does not go into timeline with video

Hi All,

I have a mov video I use for a transition that has a transparent background.

I am able to still use the file as expected on my PC running V16. On my Mac M1 with 17.1b6 (updated today) it won't have it.

The original file was generated with Adobe After Effects

I feel it might be missing a codec? VLC won't play it either and Quicktime complains that it has issues. (VLC plays it fine on the PC).

TIA

I suppose you have used the historical 'Animation' codec, which is stupidly still the default in AEFX.
Use ProRes 4444 with alpha instead.