I've experienced strange bug in Latest Xcode 11.0 My code:
let button = ASAuthorizationAppleIDButton(type: .default, style: .black)
button.translatesAutoresizingMaskIntoConstraints = false
button.cornerRadius = 10
button.addTarget(self, action: #selector(appleSignInButtonSelected(_:)), for: .touchUpInside)
Selector never called, but if I change event to touchDown, everything works.