Unable to access root view after adding SceneDelegate swift 5 - swift

Question

I have an app where users can login / sign out and the functionality stopped working recently when I added a new SceneDelegate view and moved over the code from the AppDelegate. I'm not sure why it is not working but I suspect it has to do with using the shared delegate in my signOut function.
Something strange is happening, when I tap the sign out button nothing happens. However, when I close the app and open it again, I will be signed out.
Here is the code on my home screen for the sign out button:
#IBAction func signOutButtonTapped(_ sender: Any) {
KeychainWrapper.standard.removeObject(forKey: "accessToken")
KeychainWrapper.standard.removeObject(forKey: "userID")
// send user to splash page
let signInPage = self.storyboard?.instantiateViewController(withIdentifier: "splashController") as! splashViewController
let appDelegate = UIApplication.shared.delegate
appDelegate?.window??.rootViewController = signInPage
}
This is the code from my SceneDelegate.swift file:
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
var window: UIWindow?
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
guard let _ = (scene as? UIWindowScene) else { return }
let accessToken: String? = KeychainWrapper.standard.string(forKey: "accessToken")
// If access token exists, skip login page
if accessToken != nil {
if let windowScene = scene as? UIWindowScene {
self.window = UIWindow(windowScene: windowScene)
let mainStoryboard:UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let vc = mainStoryboard.instantiateViewController(withIdentifier: "homeTabController") as! TabBarController
self.window!.rootViewController = vc
}
}
}
}

Answer 1

You've answered your own question. With a scene delegate, the window belongs to the scene delegate. The app delegate window is nil. So this line does nothing:
appDelegate?.window??.rootViewController = signInPage

Answer 2

Figured it out - add a new var in SceneDelegate
static weak var shared: SceneDelegate?
Then replace the appDelegate.window line with
let appDelegate = SceneDelegate.shared