GUI not responding on Windows 10 with an ultra wide screen

I was just getting started on a GUI application on Windows 10 and my GUI did not react at all. Even a simple example with just a button would not even highlight the button when I moved my mouse over it.

Eventually I found out that the GUI started responding if I dragged my app to my laptop screen. (my external monitor is the primary screen). Once it starts working, I can drag it back to the external monitor and it still works.

If I change my primary screen to the laptop one, the app displays on that screen and reacts as it should. This situation is workable now that I know what is going on, but ofc it’s not how it should work.

On thing that might cause this, is that I use an ultra-wide monitor. The resolution is 3840 x 1080. I also notice that the size of the gui elements is smaller once I drag it back from the laptop screen.

(I now see that this also happens to the DemoRunner. I didn’t notice it before because I had it open on the laptop screen.)


I use an ultrawide (5120 x 2160) and don’t have this problem. But then this is my primary screen and I don’t have another one. Ultrawide is not part of the equation here.

I’m not sure. Normally I would have 5120x1440, but I forgot my USB-C cable at work. So now have to use a displayport connection from my docking station, which cannot handle the higher resolution.

Point is, even though I have less pixels, my resolution is still relatively wider than yours. And it’s not my code, because the demo runner behaves the same. There could be something wrong with calculating the aspect ratio. These very ultrawide monitors are not so common, so I can see why it would be overlooked.

It’s still extremely unlikely that the resolution is the problem. Your resolution is also NOT relatively wider than mine. It’s identical to mine. The ratio is different, but that’s it.

Mine is 21:9, yours is 32:9.

It’s more likely a driver problem or the fact that it’s your secondary display than anything to do with its ratio.