Can't sign in to iTunes "temporary error (301) message.

High Sierra 10.13.

I can't sign in to iTunes. I could just a couple weeks ago. I tried downloading some songs, but kept getting error messages like it couldn't connect to the server, etc. When I try to sign in now i get a message that says "There was a temporary problem completing your request. An unknown error occurred (301). Try again later.

I've tried changing my passwords, but that didn't help.

I can log in to applemusic on my iPhone and download there, and I can transfer anything to iTunes with iMazing. But I cannot sign in to iTunes. I don't know what to do.

I didn't have this problem a few weeks ago. Can anyone help? I wouldn't mind talking to Apple directly in a phone call.