completionHandler is not triggered when using ASWebAuthenticationSession on iOS 14 iPad

When using ASWebAuthenticationSession to show a login session on iPad on iOS 14, the user can tap the background to dismiss the login session, however the completionHandler is not triggered and there is no way to tell when the user canceled the Auth session.

I am using the following code from Apple to reproduce the issue on iPad:
https://developer.apple.com/documentation/authenticationservices/authenticating_a_user_through_a_web_service?language=objc