UMG getting the screen position of a child widget

I have buttons laid out in a Grid Panel and when I use “Slot as Canvas Slot”, it returns 0,0 for the location and 0,0 for the size.

I can’t tell if the size and location really are only available for content laid out in Canvas Panels or if the “casting” to a Canvas Panel will allow the developer to reveal the location and size of the component.

Can you clarify?