Scene Transition fails after presenting from a different ViewController - ios

Question

I have a GameViewController, which transitions between different scenes, for example: CircleScene to SquareScene, back & forth with Transitions.
All of the above logic works fine, as long as GameViewController is "initial view controller".
Once I have one other view controller, above the GameViewController, the screen transitions for GameViewController doesn't work anymore.
GameViewController.swift
import UIKit
import SpriteKit
import GameplayKit
protocol ScreenManager {
func gotoSquare()
func gotoCircle()
}
class GameViewController: UIViewController, ScreenManager {
let sceneHeight = 380
let sceneWidth = 570
func gotoCircle() {
let transition = SKTransition.push(with: .right, duration: 1.0)
let newScene = CircleScene(size: CGSize(width: sceneWidth, height: sceneHeight))
newScene.screenManager = self
newScene.scaleMode = .aspectFill
let view = self.view as! SKView?
view?.presentScene(newScene, transition: transition)
}
func gotoSquare() {
let transition = SKTransition.push(with: .left, duration: 1.0)
let newScene = SquareScene(size: CGSize(width: sceneWidth, height: sceneHeight))
newScene.screenManager = self
newScene.scaleMode = .aspectFill
let view = self.view as! SKView?
view?.presentScene(newScene, transition: transition)
}
override func viewDidLoad() {
super.viewDidLoad()
if let view = self.view as! SKView? {
let scene = CircleScene(size: CGSize(width: sceneWidth, height: sceneHeight))
scene.screenManager = self
// Set the scale mode to scale to fit the window
scene.scaleMode = .aspectFill
// Present the scene
view.presentScene(scene)
view.ignoresSiblingOrder = true
view.showsFPS = true
view.showsNodeCount = true
}
}
override var shouldAutorotate: Bool {
return true
}
override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
if UIDevice.current.userInterfaceIdiom == .phone {
return .landscape
} else {
return .all
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Release any cached data, images, etc that aren't in use.
}
override var prefersStatusBarHidden: Bool {
return true
}
}
MainViewContoller.swift
import UIKit
class MainViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func btnPressed(_ sender: AnyObject) {
// Go to GameViewController
let gameViewController:GameViewController = storyboard?.instantiateViewController(withIdentifier: "GameViewControllerID") as! GameViewController
self.present(gameViewController, animated:false)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override var shouldAutorotate: Bool {
return true
}
override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
if UIDevice.current.userInterfaceIdiom == .phone {
return .landscape
} else {
return .all
}
}
override var prefersStatusBarHidden: Bool {
return true
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
}
I have tried ViewController methods (present/show) unsuccessfully. Is there anything wrong with ViewController presentation that causes scene transitions to fail? Appreciate your help.