We support SSO login as long as the login that is being done inside the in-app web-view is successful. We can see that the for login to work the Apple-specific SSO AppleConnect extension is needed, which works with iOS Safari browser. The login fails because the in-app web-view is built from Apple's WKWebview which may not support AppleConnect extension.

The mobile app can solve this by using SFSafariViewController (even though it's deprecated) within the app, which will allow our Connect Extension to be invoked accordingly.

Apple documentation recommends using the in-app webview class ASWebAuthenticationSession for web based login authentication, but ASWebAuthenticationSession does not allow the extension.

This should be resolved with the new plugin functionality in iOS 13, but until then we would need to adopt SFSafariViewController.