We recently deployed Attestation on our application, and for a majority of the 40,000 users it works well. We have about six customers who are failing attestation. In digging through debug logs, we're seeing this error "iOS assertion verification failed. Unauthorized access attempted." We're assuming that the UUID is blocked somehow on Apple side but we're stumped as to why. We had a customer come in and we could look at the phone, and best we can tell it's just a generic phone with no jailbroken or any malicious apps. How can we determine if the UUID is blocked?