I had the same problem, and i believe it's because your integrated GPU is the main GPU, and the powerful GPU (GTX 1060 in my case) is meant to enable when doing more heavy stuff like gaming. This is to conserve battery and maybe to control heat, idk. The way i fixed this was going into the BIOS when you turn your computer on, advanced tab, and switching MSHybrid to Descret. This seems to have disabled the integraded GPU, at least in my case, and the screen is running directly off the Nvidia 1060 GPU. Now when i open nvidia control panel i have options for G-sync and a load of other stuff, as before i only had the "3D settings" tab.