iOS 13: Swift - 'Set application root view controller programmatically' does not work

Question

I have following code in my AppDelegate.swift to setup root view controller for an iOS application. But it does not work. It follows Target structure (defined under General

Answer 1

I did two things. Firstly I set a Notification into SceneDelegate, then when I needed to change the RootViewController I did a Notification Post and it worked. But it's an anwful solution.

After that

My boss recommended me to change the Controllers of the NavigationController, something like this:

func logged() {
    let mainStoryboard: UIStoryboard = UIStoryboard(name: "MainTabViewController", bundle: nil)
    let mainVC = mainStoryboard.instantiateInitialViewController()

    self.navigationController?.setViewControllers([mainVC!], animated: false)
}

I know that perhaps it's not the best solution, but I see it cleaner.
I'm working now on iOS 13 and I didn't want to use deprecated things.