As above, do not use Transform Scale - it will not conform. Use styles:
Scaling will work but you’ve asked the widget to just scale up (from its centre outwards) - if you do, you must also ask it to move:
But don’t, it will probably just overlap. Consider working with Image Size and ensure the image you’re using is large enough.
As soon as you start fiddling with scale, and translation in general, the Desired Size of the widget is no longer reported accurately (I mean, it is, but not to the human eye, it is not); other elements and the parent container depend on it for the layout.
UMG is not pixel perfect everywhere.