Black Screen when using a Login page

Hello,

Here is my code:

**AppDelegate.cs**

```
public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{
Window = new UIWindow(UIScreen.MainScreen.Bounds);

if (isAuthenticated)
{
Window.RootViewController = new RootViewController();
}
else
{
Login screenLogin = new Login();
screenLogin.OnLoginSuccess+= ScreenLogin_OnLoginSuccess
Window.RootViewController = screenLogin ;
}

Window.MakeKeyAndVisible();

return true;
}

private void ScreenLogin_OnLoginSuccess(object sender, EventArgs e)
{
isAuthenticated = true;
Window.RootViewController = new RootViewController();
Window.MakeKeyAndVisible();
}
```

**RootViewController.cs**
```
public partial class RootViewController : UIViewController
{
public SidebarController SidebarController { get; private set; }
public NavController NavController { get; private set; }

public override void ViewDidLoad()
{
base.ViewDidLoad();

NavController = new NavController();
NavController.PushViewController(new Home(), false);

SidebarController = new SidebarController(this, NavController, new Menu());
}
}
```

My Login screen is a UIViewController. NavController is a class that inherits from UINavigationController. The fundamental is: if user is not authenticated, so, i show the login page. When the user enter the correct credentials, i call the event 'OnLoginSuccess', that is signed in AppDelegate. So, i change the isAuthenticated var to true and set my RootViewController class as Window.RootViewController and call Windows.MakeKeyAndVisible();

When i testing this code at emulator, works fine (iphone 5s, iphone 6s+, ipad pro 9.7). But, in a real device (iphone 6 and iphone 6s) only appears a Black Screen after the login.

All real devices are using iOS 11.1 and 11.0.3.

I'm little bit frustrated.

Thanks for the help!