Render Skia or Stride, Wrong resolution on FullScreen, while 2 screens connected

Using 2 Screens (one 4k at 150% and the second 1080 at 100%)
Fullscreen on the first 4k monitor, all fine
Fullscreen on the second HD monitor, shows wrong resolution and aspect ratio.

Could be a DPI issue, does it work if you set both screens to 100% (and restart windows)?

As soon as the resolutions are different, it behaves wrong.