The view.layer.presentation() 's value is not accurate.

I add two view on screen. One is the blue view, other is orange view.

And I use CADisplayLink to change orange view 's frame according to the blueView.layer.presentation.frame

As expected, the orange view should cover the blue view completely, but we can see a gap and we can see a little part of blue view during keyboard animation. Here is demo code:

class SecondViewController: UIViewController {
   
  let textField = UITextField()
   
  override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    self.textField.resignFirstResponder()
  }
   
  lazy var displayLink = CADisplayLink(target: self, selector: #selector(self.onDisplayLink))
   
  @objc private func onDisplayLink () {
    self.realBox.frame = CGRect(x: self.realBox.frame.origin.x, y: self.blueBox.layer.presentation()!.frame.origin.y, width: self.view.bounds.width, height: 100)
  }
   
  let blueBox = UIView()
  let realBox = UIView()
   
  override func viewDidLoad() {
    super.viewDidLoad()
    self.view.backgroundColor = .white
     
    textField.frame = .init(x: 100, y: 100, width: 100, height: 100)
    textField.backgroundColor = .red
    self.view.addSubview(textField)
     
    realBox.backgroundColor = .orange
     
    blueBox.backgroundColor = .blue
    blueBox.frame = .init(x: 0, y: self.view.bounds.height - 100, width: self.view.bounds.width, height: 100)
    self.view.addSubview(blueBox)
    self.view.addSubview(realBox)
    realBox.frame = .init(x: 0, y:self.view.bounds.height - 100 , width: self.view.bounds.width, height: 100)
     
    NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillChangeFrameNotification, object: nil, queue: .main) { noti in
      let userInfo = noti.userInfo!
      let endFrame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! CGRect
      let isOpen = endFrame.intersects(self.view.bounds)
      self.blueBox.frame = .init(x: 0, y: isOpen ? self.view.bounds.height - 100 - endFrame.height : self.view.bounds.height - 100, width: self.view.bounds.width, height: 100)
    }
     
    if #available(iOS 15.0, *) {
      self.displayLink.preferredFrameRateRange = .init(minimum: 60, maximum: 120, preferred: 120)
    } else {
      self.displayLink.preferredFramesPerSecond = 120
    }
    self.displayLink.add(to: .main, forMode: .common)
  }
}

So how to get an accurate value of the layer currently displayed on screen?

Here is the video: https://github.com/luckysmg/daily_images/blob/main/RPReplay_Final1661168764.mov?raw=true