video files hang when downloading from iCloud

I see that there have been people note this in the past, but it's always given an answer that it's a problem on the user's side. I assure you that's not the case here.

When I'm trying to download videos from iCloud (in the "Photos" section) a small amount of it starts, then it hangs. It may eventually start up again, but the time to complete just creeps up into the "days" range, and the file transfer stops. This happens almost every time I try to download a video, unless it's extremely short.

Refreshing the browser doesn't fix it. Logging out and logging back in doesn't fix it. The problem happens on all computers in my house, it isn't a specific one. I've tried it on wireless and wired, and there's no difference. On the wired computers, they are connected to my router on Gigabit switches and direct Ethernet. I have Gigabit fiber to my house, and no problems with anything else in transfers - it is only iCloud.

I'm paying for this storage service, I'd like to be able to use it. What can you do about it?