How do I resolve a HDR bug? It turns on by default.

[HassleDuff]

I recently got a LG 1440p Ultragear that has DisplayHDR400. I'm aware of its HDR limitations, so I try to leave it disabled. Strangely, when I restarted this game with the new monitor, and I tried the benchmark---after adjusting settings to account the new res---the game just turns on HDR automatically. EVEN WHEN THE HDR OPTION IS TURNED OFF.

It happens even when I start the game proper; I noticed it because the Steam notification and the whole game looks greyed and washed out. Turning on HDR corrects itself back to its original colors, but I never planned to keep the game with HDR enabled.

Seemed like this is a DirectX 12 issue, because when I switch back to DX11, the "AutoHDR" was never prompted and the colors are back to normal. Likely because the HDR option has been crossed out entirely. I want to keep DX12 for the performance boosts, so I have to ask if there's a way to fix this without switching DX versions?

[UPDATE]

Upon further testing, it seems the DX12 alone isn't the issue, but the Exclusive Fullscreen itself. When I set the window setting back to Fullscreen, the colors are normal. The HDR option is completely disabled, and weirdly, the option only works when I set the window setting back to Exclusive Fullscreen in-game. Weirdly enough, doing the in-game approach kept the colors as intended. However, when I close the game and opened it back--with the HDR still set to off, mind you--the washed out greyish colors returned. So the bug is Exclusive Fullscreen related. If only I knew how this option affects how colors are presented.

[Rudiger]

H3 has the same issue if you are going to move to that now that H! & H2 servers are closing down.
I just Alt + Tab to desktop, go into display settings, turn on HDR and then turn it back off again. This fixes it.