Ok - I caved, I bought an HDR display. Quick background. Yes I've rebooted, reinstalled gfx drivers, tried turning off freesync, on freesync, changing hz, matching hz, disabling the overlay, etc etc, etc....
The problem is, ever since adding an HDR monitor, while in-game, if I adjust volume, the screen will flash black, show the overlay, once the overlay for the volume is gone, the screen flashes black again. What it is doing is actually turning HDR OFF and ON each time.
Now - Windows 10 , it's running in HDR, it's enabled in color settings in windows, it's enabled in nvidia control panel, brah brah brah... Now - here's the kicker, it doesn't even matter if it's an HDR game or SDR game, adjusting the volume in game will make any game flash black, until the over lay shows, and then disappears and then flashes again. My buddy (has an HDR screen different brand / model, same problem)
For anyone who cares, it's an lg-34GK950F-B, and paired with a 2080ti,... After hours of google-foo I can't find similar issues, only relating to a "logitech keyboard problem" but I'm not using a logitech keyboard.
Does anyone else have this problem? Sure, if I don't adjust volume it's fine and HDR works great when it's supposed to, and stays off when it's supposed to, but, I change my volume. A lot.
If anyone has had a similar expierience it would be much appreciated. A video would probably be beneficial so maybe I'll try to post something up tonight.