Same issue, HDR turned on in Windows, when adjusting audio volume in Non-HDR Game with Logitech G910 Keyboard, HDR turns on.
Shouldn't be keyboard related; Win/Superkey+G (Game Overlay by Windows) => same issue.
(Everything regarding HDR in Windows turned on)
Monitor:
(2x BenQ EW3270U 32" 4k HDR)
With HDR Black text on white background looks kind of unsharp in many apps compared to HDR turned off. (One of the bad examples: Legacy Win10 GUI-Components, Dark Mode programs look fine like Visual Studio)
How to fix black screens by unnecessary HDR-Mode changing?
When non-HDR app opened in fullscreen like e.g. the game CSGO, turn HDR off, ignore overlays, any overlay forcing HDR should be calculated down to non-HDR and it should not force my screen to turn on HDR again, when changing mode I get ~3s black screen...
Additionally a option per App HDR, or even per Subapp like a Chromium Tab for YouTube or Netflix;
just an option to turn on HDR if available for the current main (sub)app excluding volume bars and so on.
Example:
I just want to open Netflix app, YouTube Tab, Prime Video Tab, the Website or App returns true on the HDR question, screen should turn on HDR if currently opened with focus and in Window Fullscreen, Fullscreen-Window (without borders), Fullscreen.When focusing on secondary screen, the currently HDR turned on main screen should not change mode as well.