Hello,
I’ve noticed recently that the nvidia fast vsync option stops working if you have a render scale that isn’t 100% (simply go in game, choose 75% render scale for example and you’ll see that fast sync no longer caps the fps at double your display rate, which it should do if it was working properly - you could leave fps uncapped at 400 and it would show 240fps cap if you had nvidia fast sync on, since it would cap at double your display refresh rate: 120hz = 240 fps cap).
This happens 100% of the time you change resolutions (the moment you change back to 100% render scale it works again instantly and vice versa), so it’s for sure a bug that needs adressing.
Don’t know if it’s related to recent nvidia drivers, went back to 511.23 and it’s still happening, might go back further but still.