Dragging UI element using Touch, moving more than finger.

I’m using Input.touches[0].position to drag an UI element horizontally.
In the small Unity preview it’s nearly perfectly following the pointer, so I didn’t think there was a problem.
But on higher resolution devices (and also in Unity when maximized) the element moves so much faster than the pointer, maybe even double.

I could try to find a magic number based on the horizontal resolution to reduce the motion per frame by but I’d rather know what the problem is exactly.

Super simplified this is my code:

RectTransform UIElement;
void Update(){
    UIElement.anchoredPosition -= new Vector2(Input.touches[0].deltaPosition.x, 0);

Found the answer:
If your canvas is set to overlay, it will scale.
divide your motion by Canvas.scaleFactor