Screensaver not loading "Favorite" photos after Monterey upgrade

So, trying to get my screensaver to load using images from the Photos app. I had this working fine before the upgrade, but now I just get a black screen with the time showing. I use the “Favorites” album, but for testing purposes have also tried others.

For many of the photo based screensavers, I see nothing in the small preview, nor anything when hitting the button to load “full screen preview” mode. For a few, like the “Photo wall” one, it correctly loads my images into the small preview, but still nothing in full screen preview (or actually running) modes.

It feels like a permissions issue, but as there are no error messages, I really can’t tell what’s going on. Any ideas?