Downloading world fails

As seen in the attached video, when I attempt to download my world, it gives me an error message. 

 

This seems to be different from REALMS-474, as it doesn't have anything to do with uploading or replacing worlds. This issue did not happen to me before 1.19.30, but I'm not sure if it's directly related, or just coincidental timing.

 

This has happened a few times in a row, and still seems to happen with a game restart.