This has been going on for at least a couple of hours for us: notarizing doesn't complete. Our last job ran for over 90 minutes before CircleCI timed it out. We're using xcrun notarytool submit with the --wait option; it contined to say "Current status: In Progress" for, as I said, 90 minutes or so. (Normally it takes about 70 seconds.)
https://developer.apple.com/system-status/ says everything is normal. This does not seem to be the case for us. 😄