Pointer lock Request doesn't honored by system

I have an app which uses mouse to interact in side the app , i want to lock pointer to prevent it from overlap with system gesture on iphone se 2020 like if pointer reach up right corner it grabs notification window

i used method like here in WWDC2020 https://developer.apple.com/videos/play/wwdc2020/10617?time=461 with view controller and called func which should change pointer state from viewDidLoad func

import UIKit

class ViewController: UIViewController {
   
  var pointerLocked :Bool = true
  override var prefersPointerLocked: Bool
  {
    return pointerLocked
  }
  override func viewDidLoad()
  {
    super.viewDidLoad()
    changePointerState(newState: false)
  }
  
  func changePointerState(newState:Bool)
  {
    pointerLocked=true
    self.setNeedsUpdateOfPrefersPointerLocked()
   
  }

}