Purchased movie files corrupt?
I have a few hundred movies purchased from either iTunes or the new TV app. Today, on my Mac, I tried to watch one of my recent purchases. I got a blank window with a spinning beachball cursor for several minutes. I tried another recent movie, same result. So I right-clicked on one of them and chose Show in Finder. The movies in question, instead of having a normal icon for a movie file (with the artwork), have a File Viewer icon with a magnifying glass.
The movies are titled properly, such as "Toy Story 4 (1080p HD).m4v" If I double-click one of these files, File Viewer opens with an information window. None of the information there is useful. On a hunch, I arranged the movies by Date Added, and it appears that my most recent 61 purchases (out of 539 since 2008) have this situation with the File Viewer icon, and won't play.
This is very strange because at least 12 or so of those movies I had previously watched with no problem.
I know I can easily delete and re-download all these movies, but I'd like to know what caused this! Also, re-downloading 61 movies is annoying and will take a big chunk of my monthly data plan.
iMac 27", macOS 10.15