Recently I've implemented Sign In with Apple in my IOS app. For testing, I sign in, sign out many times in a day.
It works as expected mostly. But I found sometimes when I try to sign in, after verifying with Face ID or Touch ID, it may show a "Sign Up Not Completed" error, then an alert "Could Not Connect: Make sure you are connected to Wi-Fi or your cellular network." shows up. I'm sure that the internet connection is fine, I can download other apps from AppStore via Wi-Fi or 4G at that time. But when I try Sign In with Apple in these apps, they show the same error. But the system status page is always shown Sign In with Apple is available. This situation usually does not last 10 minutes. When Sign In with Apple is an app works, other apps, and my app work. This happens up to three times a day.
How can I solve this issue? How the make sure it works every time?
