There is a setting in Windows where you assign games to a graphics card. You may want to check out both available options. Windows always overrides the identical feature in NVIDIA's driver which is therefore entirely pointless. My old NVIDIA laptop has this feature on the 980M. Not sure if it still exists in more recently devices.
I cannot test this on my G5 KF (300 Hz, but permanently underclocked to 60) because it recently broke and is getting repaired (hopefully).