I have it back on my computer, though I'm not sure which version it is. I did the following:
Hard boot after computer being off all night and morning.
Plugged wireless device into different slot.
Closed Bandlab page when it opened up.
Declined all add-ons.
Not sure which, if any of these, helped, but it downloaded and installed in about 30 minutes. This time, there was only one file to download, so the "progress bar" only read "0/1." Maybe it was too much to expect to download all three packages, when so many people are hitting the servers.
The version I now have is 24.04.1 build 28. I think that is the new one. It played fine, except for the weird zapping noise I have been having problems with, but that's another story.