We need to read the value for userActivity.referrerUrl when the app is accessed through a Universal Link, which when using the UIKit lifecycle we can easily do by implementing the method scene(_: UIScene, continue: NSUserActivity) in SceneDelegate and filtering for activity type of NSUserActivityTypeBrowsingWeb.
When the app uses the SwiftUI lifecycle that method doesn't get called, even though the app is correctly configured to use AppDelegate and SceneDelegate (through the @UIApplicationDelegateAdaptor wrapper). I can confirm that the setup is correct because the method scene(_: UIScene, willConnectTo: UISceneSession, options: UIScene.ConnectionOptions) in SceneDelegate is called on app launch.
The obvious SwiftUI way of achieving the same would be by using the .onContinueUserActivity(NSUserActivityTypeBrowsingWeb) modifier, but that doesn't work. Is this a bug?