Thanks @hunterk for taking time to investigate this, so now we know it was intentional. My idea take benefit of the autoscale option, is to set 4 elements shifted to each corner,
When the screen resolution or RA windows changes, these elements always stay on the edges, while applying vertical and horizontal elements centered on the back, so those will fill the empty space when those border elements move from each other.
That worked great for a landscape overlay, but when i tried a portrait one, i see the elements shift to the sides or stay in the horizontal border, but stay always vertically centered.
I made a 16:9 screen ratio portrait overlay @ 1080x1920, and when i tried that on a phone that has a taller screen ratio, (18,5:9) . I got a vertically centered overlay, with the screen or view port stick or shifted to the top edge. (like it does on landscape mode)
just like this:
Anyways, I’m gonna put this here so maybe its useful for some one, or maybe i forget what i did:
Ended up, doing this: made the portrait overlay at the most common screen ratio used mobile phones nowadays ( 9:20 ) at a resolution of 1080x2400.
On 9:20 and 9:18.5 aspect ratios screens, i set the video scaling to 4:3, and i get the game screen on place with the overlay.
For a smaller aspect ratio (9:16) i set video scaling to CORE PROVIDED to fit in the overlay viewport space.