There are several ways to “sync” your video card with your monitor with settings in both the video card driver and MSFS. I would recommend playing with them as you might have a conflicting setting.
My monitor & AMD video card both support freesync but at the end of the day, disabling that and turning on vsync within the sim gets me smooth sim performance. Also, I’ve found that running your monitor at its default refresh rate typically will provide the best performance.
I know your set up is a little different with an Nvidia card but swap freesync with g-sync and you have a similar situation.