TouchPhase.Began not called on Android build.

Unity Engine
1

With simple touch and hold for a second or two I am getting TouchPhase.Moved and Ended but about 1/3rd of all touches are missing the Began!

private void OnEnable()
    {
        EnhancedTouchSupport.Enable();
    }

    private void OnDisable()
    {
        EnhancedTouchSupport.Disable();
    }

    void Update()
    {
        touchCount = Touch.activeTouches.Count;

        if (touchCount == 1)
        {
            touch0 = Touch.activeTouches[0];

            switch (touch0.phase)   //first touch
            {
                case TouchPhase.Began:
                    Debug.Log("ONE TOUCH BEGAN at " + touch0.screenPosition);
                    break;

                case TouchPhase.Moved:
                    Debug.Log("ONE TOUCH MOVED at " + touch0.screenPosition);
                     break;

                case TouchPhase.Canceled:
                    Debug.Log("ONE TOUCH CANCELED at " + touch0.screenPosition);
                    break;

                case TouchPhase.Ended:
                    Debug.Log("ONE TOUCH ENDED at " + touch0.screenPosition);
                     break;
            }
        }

        else if (touchCount == 2)
        {
            Debug.Log("TWO TOUCHES");
        }
    }

This was tested on a Samsung Galaxy A21s.
Any ideas? Is this a bug or am I doing something wrong?
Just tested on an old Nexus 7 and touches seem to be working OK on that (but Audio not - but that is another thread).

2

Update:
I had VSync set to 2 giving a steady 30 FPS. Resetting to VSync to 1 has hidden the problem for now at least.
Can anyone explain to me what is happening here?

[Also setting
Application.targetFrameRate = Screen.currentResolution.refreshRate / 2; has no effect. Still getting 60 FPS]