Thanks (as always) for your helpful advice, Quinn. I'm hitting this too -- although I've only been waiting for 36 hours at this point. Interestingly, our app has already been notarised many times while in development, each time in a couple of minutes. But we've transferred the same app to a new company / org before release, and now notarisation seems to be taking a very slow path. So this seems to be a delay on new organisations, at least in our case, rather than anything to do with the code being notarised?

To bump an old thread... UUID is now Sendable! https://developer.apple.com/documentation/foundation/uuid/

I have also seen this problem with xcrun altool for several days. Using Transporter worked about the problem for me (but is a bad workaround long term because it prevents scripting). I've submitted Feedback FB9742349 on this problem, please consider filing your own Feedbacks / Radars.