Question How to realize a fixed aspect ratio window during resize in UWP

I'm creating a 2D board game, and want to deploy it as an UWP app in the Microsoft Store. Because it's a board game, I would need a 4:3 ration for the window, which means that what I would need is, that the user is able to size the window, but the aspect ratio of the window is always 4:3. Can this be achieved?

I looked through a lot of internet pages, suggestions and comments, but whatever I tried so far didn't work out. Maybe I'm doing something wrong and didn't mention it.

What I've tried so far:

* using the Update() function, querying Screen.width and Screen.height, and if it changed to the previous values, calling SetResolution() with the 4:3 corrected values -> a lot of fllickering and window jumping

* using UnityEngine.WSA.Application.windowSizeChanged += myWindowSizeChanged, and inside the WSA callback, calling UnityEngine.WSA.Application.InvokeOnUIThread(() with a Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().TryResizeView(new Windows.Foundation.Size { Width = w, Height = h }); call -> also a lot of flickering, and TryResizeView returns False most of the time (why?)

Does anybody have a good idea how to achieve my goal. I would be more than happy!

Kind regards,

Markus