Finder doesn't show preview thumbnails

Hi,

I am on macOS Monterey (12.0.1) and a couple of days ago all my thumbnails are no longer showing a preview image.

I have tried all remedies I could find, restarting, deleting the plist, making sure Preview is selected as default, still same problem.

I created a 2nd admin account on my Mac, and it's working there, but not on my main account.

Before I start moving everything over, what else could I try?

Thanks,

MB