title: Why is UIApplicationDelegate method `application(_:configurationForConnecting:options:)` not called reliably
body: <p><strong>Issue:</strong></p>
  <p>I find some unexpected behavior regarding the AppDelegate method <code>application(_:configurationForConnecting:options:)</code>.</p>
  <p>The documentation states:</p>
  <blockquote>
  <p>UIKit calls this method shortly before creating a new scene.</p>
  </blockquote>
  <p>I would expect that this is the case every time the app is launched.<br />
  The method is indeed called when I launch my app for the first time, however for all subsequent launches, <strong>it is not</strong>.</p>
  <p><strong>Reproduce:</strong></p>
  <p>I have a very simple test case to reproduce:</p>
  <ul>
  <li>Xcode 12 &gt; Create new Project &gt; iOS &gt; App (UIKit/Storyboard)</li>
  <li>add a debugging statement in the method in <code>AppDelegate</code> like so:
  <pre><code>  // from Apple's sample project:
    func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -&gt; UISceneConfiguration {
        // Called when a new scene session is being created.
        // Use this method to select a configuration to create the new scene with.
        print(&quot;I was called!&quot;).  // &lt;--- debugging statement
        return UISceneConfiguration(name: &quot;Default Configuration&quot;, sessionRole: connectingSceneSession.role)
    }
  </code></pre>
  </li>
  <li>run the app &gt; &quot;I was called!&quot; gets printed in the console</li>
  <li>run the app again &gt; nothing get's printed.</li>
  </ul>
  <p><strong>Question:</strong></p>
  <p>Why is <code>application(_:configurationForConnecting:options:)</code> not being called on second launch?<br />
  (Is it expected behavior, if yes why / Is it a bug by Apple)</p>