Help!...Prevent click thru on Gui

Hi
Using the following method to check if any given touch or click point is ‘over a Gui element’ to prevent click thrus on Canvas Gui elements. The problem is that it seems to work on the desktop, but only sometimes when deploying to mobile. I’ve also attached both Graphics Raycaster and Canvas Group components to my Canvas. The latter with everything enabled (Interactable, Blocks Raycasts, Ignore parent Groups). (see below)

Can anyone suggest why my Canvas button touches are NOT being blocked on mobile?

public bool PointIsOverUI(int x, int y)
    {
        var eventDataCurrentPosition = new PointerEventData(EventSystem.current);
        eventDataCurrentPosition.position = new Vector2(x, y);
        tempRaycastResults.Clear();
        EventSystem.current.RaycastAll(eventDataCurrentPosition, tempRaycastResults);
        return tempRaycastResults.Count > 0;
    }

Seems like overkill when EventSystem.current.IsPointerOverGameObject() exists.

Have you ever tried with an AR project?