The G752vs with i7 6700HQ CPU comes with either a 120Hz or 60Hz display.
In the NVIDIA control panel, can you change refresh rate to 60Hz? Is there even the option to change?
Check the Device Manager for any Display Adapter problems noted. Check the NVIDIA driver.
I think I ran across this problem before, reinstall NVIDIA driver. Delete existing driver then reboot, allow Windows to reinstall. Windows should detect the NVIDIA display adapter and install a generic driver, then go to NVIDIA website and download latest driver.
I use GeForce Experience to download latest drivers.
Good Luck
G752VSK, G75VW-3D, G51J, G1S
Homebuilt Windows Server