I'm not sure why, but I was able to resolve the issue by following these steps: 1.Turned on "Advanced Data Protection for iCloud" in iCloud settings. 2.Added a "Recovery Contact" in iCloud settings. 3.Went to Xcode -> Preferences -> Accounts and signed in again with the same account. Alternatively, the issue may have been resolved by some server-side error on Apple's end that got resolved over time. Just for reference.