Gsync issues

[Sn8ke]

I am using two 1080's in SLI, I have a confirmed g sync monitor (ACER XB280HK). I've used g sync in DCS relatively successfully, However recently when I have g-sync on the NVI, v-sync set to app controlled and off in game, I am getting a displayed FPS greater than 120, well above my monitor's refresh rate of 60 hz. I have the latest Nvidia drivers 382.33. I even used DDU to roll back to drivers which g sync worked with negative results. Has anyone had a replication of this issue? Is it possible the g sync is b/o within my monitor's hardware? Thanks for any helpful input.