Can't Download Purchased Movies to Mac - Error 21 on Apple TV MacOS App

As the title says, I can't download several movies I've purchased. Others are fine. I get an Error 21 message and instructions to check my connection. I've searched the communities there appears to be a common response (If you can't watch or stream movies and TV shows in the Apple TV app - Apple Support) with no indication it works. (It didn't do anything for me.)

However, I do see a commonality on those that won't download - they are all part of a package, even though a single movie was able to be purchased. They are all of the format movpkg, whereas a regular single movie downloads as an m4v. If the pack can't be downloaded individually, then it shouldn't be able to be sold that way IMO.

Wondering if anyone know a way to get these downloaded.

Many thanks for any help you can provide.