Windows 10: How to disable HDR toggle within being in HDR mode

Hi,

A short introduction to my problem, and what I've done so far:

1) I've been trying to set up HDR with my PC running to my TV. Both are HDR compatible, I've checked my HDMI cable is HDR capable (successfully connect this to my PS4 Pro and triggers HDR).
2) Initially, I connect the PC and activated HDR on the TV side (HDR is toggled per HDMI port on my TV). At first, the PC displayed on my TV as expected, but with the HDR toggle inside Windows 10 to off. Naturally, I toggled HDR to on...
3) Next, my screen went black and the PC disconnected from the TV input. Now, the only way to achieve a picture again is to turn off HDR on the TV side.

My question - firstly, am I missing something in this process with regards HDR working properly, and secondly, is there a way to untoggle the HDR in Windows without have HDR enabled? The option only becomes visible once HDR is enabled.

Thanks, Jonny

:)

 

HDR fullscreen problems

Version: Windows 10 17134

GPU: NVIDIA 1080 Ti (Driver 397.31)

Display: LG OLED 55" B6P

Problem: Windows HDR implementation barely works properly. Here's a list of issues I've seen so far:

1: SDR applications that are not exclusive fullscreen start in HDR mode, distorting the colors. If an OS overlay [such as the volume overlay] come up, the display will go blank until the overlay dissapears.

2: SDR applications that are exclusive fullscreen go blank. From what I can see, my display is in SDR mode, so I'm guessing there's a mismatch between Windows trying to output HDR content and the display receiving it. [And no, the problem is on Windows
end; the display can handle HDR just fine on other systems]

3: I've had a case where an SDR application, on exit, somehow resulted in the system HDR setting being disabled. I've also had another case where on exit the system is reporting its in HDR mode, but outputting SDR even on the desktop.

So in short: Windows is not managing HDR properly.

 

Nokia N9 HDR mode

Is there any chance N9 gets HDR mode in camera?