FoLLgoTT

I got the same problem. But when I use the overload with refreshRate of CustomResolution() it works. With ColorFormat I never got it to work.

FrequencyInMillihertz is also wrong. It shows 60 Hz instead of 59,94 Hz. Only the PixelClock seems to make the difference and so the real refresh rate is correct. NVIDIA control...

Ok, I suspected that the cause is more inside Windows/drivers. Thank you for the answer.