I have been seeing the same thing for a couple months now. It's super-frustrating. I submitted a Feedback (FB8795763) about a month ago to Apple and have received no response.

I am seeing inconsistent CloudKit reliability ever since iOS 14 was released. I don't always get push notifications and the CloudKit Dashboard logs never appear.

Also on: https://stackoverflow.com/questions/63241643/cloudkit-server-to-server-auth-keep-getting-401-authentication-failed/