UMG widget stretching vertically in 4:3 resolution

Hi, I am currently facing scaling issues regarding the UI when I am viewing our app on the iPad pro. A further check reveals that the UMG widget does not scale correctly for any 4:3 resolution.

This is the original look of the buttons for the iPhone 6+.

The iPad 3,4, Air setting stretches it.

Fiddling with the DPI scaling to set it to 1.0 did not help much either, it is still stretched vertically.

I have tried various means, including putting the widget into a scale box in a new widget but to no avail, my UI is still stretched.

Any help would be appreciated. Thanks!