Is the 'Sign in with Apple' feature really going to be broken throughout ALL iOS 14 (Xcode 12) versions since Xcode 12 beta? If your iOS 14+ app only relies on Sign in with Apple as an authentication method, this is a hard roadblock. I wonder how many countless hours are lost by both Developers & Apple's App Reviewers because of this issue.

It turns out that I can connect the device to Mac, and use QuickTime Player to record the incoming call screen.

Apple already knows your account holder info. That email is 100% scam. It is even asking you to provide photocopy of your passport... It has been a while since I received this kind of blatant scam email. You should change your email provider if your current email provider can't filter out scam messages like this. e.g. Gmail does good job of filtering out scam emails.