Disabling the device might make windows send “safe” resolution, refresh rate, bit depth, HDR etc
Its definitely not windows sending a safe resolution and / or refresh rate, i checked the monitor OSD to confirm this
HDR works fine
I discovered that the monitor is working fine without disabling it in device manager if i select a limited range under “Output dynamic range” in the NVIDIA control panel, i have tested this in 8, 10 & 12bpc and at 60, 120 & 144hz, i am running at the native resolution for the monitor which is 2560 x 1440 so something doesn’t like the full range
im going to check again at lower resolutions and full range to see if i can rule out a HDMI bandwidth issue