If your connectingSceneSession is not called, check your app Info.plist:
UIApplicationSupportsMultipleScenes = true (YES)
UISceneConfigurations : empty dictionary (array)
<key>UIApplicationSceneManifest</key>
<dict>
<key>UIApplicationSupportsMultipleScenes</key>
<true/>
<key>UISceneConfigurations</key>
<dict/>
</dict>
Topic:
Developer Tools & Services
SubTopic:
Xcode
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