iOS screen captured post false notification but I not stop recording

Question

when my app is recording，I click recording in statusbar on the left, then it post the captured false notification below with alert, but I havent click stop button in alert; then it post the captured true notification when I click cancel button.

it should not post notification when I click the stop button?

it was some bug for this problem?

    private func addNotificationForCaptured() {
        NotificationCenter.default.addObserver(self, selector: #selector(screenCapturedDidChange), name:  UIScreen.capturedDidChangeNotification, object: nil)
    }
    @objc func screenCapturedDidChange(noti: Notification) {
        if let screen: UIScreen = noti.object as? UIScreen {
            print(screen.isCaptured)
        }
    }

iphone recording alert