Unable to switch to full screen after changing size of window

[Capucke]

Hello,
Thanks a lot for this project.

However I noticed some issue :
When at the start of my unity application I click on the rectangle icon of the top right hand corner to go to full screen it works.
But when I click on that same rectangle after I have already changed my window resolution, it doesn't allow me to go to full screen anymore.

I am on Windows 10, and Unity 2019.4.15f1

[rc12234]

I faced the same problem. This is due to the fact that the Windows "full screen" button is part of Aero Snap, for which I found a separate handler in the Update method in the code. Just comment or delete or remake for your task out this part of the code.
else if (!Screen.fullScreen && setWidth != -1 && setHeight != -1 && (Screen.width != setWidth || Screen.height != setHeight)) {
// Aero Snap detected. Set width by height.
// Necessary because Aero Snap doesn't trigger WM_SIZING.
setHeight = Screen.height;
setWidth = Mathf.RoundToInt(Screen.height * aspect);
Screen.SetResolution(setWidth, setHeight, Screen.fullScreen);
resolutionChangedEvent.Invoke(setWidth, setHeight, Screen.fullScreen);
}