[SOLVED] Games will suddenly not run in fullscreen mode unless they are the same resolution as my desktop.

[chinagreenelvis]

I don't know what update did this, or for what, but ever since moving to a 1440p monitor, I've noticed that it's impossible to get a game running in fullscreen mode at any resolution lower than my desktop.

Even if I manually lower the desktop resolution, if I manage to get the game running and alt-tab out of it, the desktop returns to its native resolution instead of the one to which I had it set.

I've also noticed that games will not run in fullscreen borderless at resolutions lower than what the desktop is set to. They will always default to the desktop resolution, even when the setting in-game is changed.

I'm running:

Windows 10 1809 (Build 17763.316)

GTX 1060 (Latest drivers, 457.09)

Monitor is an LG 27GL850, connected through DisplayPort.

Edit: I have just discovered the refusal to go or return fullscreen seems to be based on whether or not any other open windows exist, as if the fullscreen application refuses to take focus.

Edit2: Solved. See below.

 

[Nemesia]

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1809	Redstone 5	October 2018 Update	17763	November 13, 2018	November 10, 2020	January 9, 2029
1903	19H1	May 2019 Update	18362	May 21, 2019	December 8, 2020	N/A
1909	19H2	November 2019 Update	18363	November 12, 2019	May 11, 2021	May 10, 2022
2004	20H1	May 2020 Update	19041	May 27, 2020	December 14, 2021
20H2	20H2	October 2020 Update	19042	October 20, 2020

Might want to update to at least 1909. November 2018 is far away. Could literally be an OS issue.

 

[chinagreenelvis]

Unfortunately, updating Windows is not an option since 1909 introduces unacceptable issues with my WMR VR headset.

This has never been an issue before, and I have had the same version of Windows since well before this problem manifested itself.

 

[Nemesia]

Unfortunately, updating Windows is not an option since 1909 introduces unacceptable issues with my WMR VR headset.

This has never been an issue before, and I have had the same version of Windows since well before this problem manifested itself.

Use DDU to uninstall your GPU drivers and reinstall the latest.

 

[chinagreenelvis]

I have also just discovered the refusal to go or return fullscreen seems to be based on whether or not any other open windows exist, as if the fullscreen application refuses to take focus.

 

[chinagreenelvis]

Well, I figured out the problem and it turns out it has nothing to do with my drivers, Windows version or display. It's entirely my own fault.

I wrote a window management program in AHK that rearranges applications when the resolution changes. Older versions of my program didn't produce this issue but a recent re-write must have, since disabling it returns everything to normal behavior.

derpface.jpg

Edit: A more detailed explanation - for some reason, I used the command WinActivate on rearranged windows, so when the program detects the resolution change caused by the game, it moves other windows around and then makes them active, which causes the game to minimize.