What Happened to my Thumbnails?
In my Apple TV library, I have MANY MANY movies & TV shows that come from videotapes that I taped off of TV and converted into digital files. These are NOT items that were purchased from the Apple store. Before converting to Catalina, each clip/show/movie had a thumbnail of a frame from the clip. It was chosen automatically from the clip about 5 seconds, in but I could also pick my own cover image - find the frame I wanted, freeze it, right click and select it to be my 'cover art'.
Now, with Catalina, all those images are gone - on every clip that is not a purchased item, I have the null image, the gray box with an outline of a TV screen.
How can I get them back? The option to right-click and select my own is also gone.
Mac Pro