Bridge 2021 does not display video thumbnails

I'm trying to get Bridge 2021 to display the thumnbails of video files, (mp4 and mov) but it just doesnt work.

I tried the various tips online such as purging cache, increasing thumbnail max size, embedded vs high quality, right-clicking on a video file and selecting purge cahce for selection,... nothing works.

Another weird thing is that is I right-click on a video file and select Open, nothing happens. But if I select Open With... and select Quicktime Player 10.5 (which is the one I have), it does open.

What is (not) happening?

Thank you!!!!