Thanks butterdog!

Sadly, it worked only one time and I can not replicate it again.. Luckily on my HDR4 monitor is game playable in HDR, but only at night when all lights around are dimmed.. Crazy error..
And developer neither steam stopped support for this game gem.- :_(

Thank you

Sadly @butterdog that fix does not work for me. Not sure why, it kind of does if I play the game in a broken windowed mode state but if I want it to take up my entire UW 2560x1080 monitor in borderless fullscreen it will break again.

The only thing that works is what is in the guide above us.

Not to discount this fix, but I wanted to keep 10 bit output enabled. You can change this setting just for Nex and it won't affect anything else;

1. Open NVIDIA control panel
2. Go to 3D Settings > Manage 3D Settings
3. Switch to the Program Settings tab
4. Wait for the game scanning to finish
5. If it finds Nex select it from the drop down, otherwise click the Add button and it should be in the list, otherwise add the executable manually
6. With Next selected in the dropdown scroll to 'Antialiasing - Gamma correction' and turn it OFF
7. Click the Apply button at the bottom of the window, restart game

based