I was playing around with my in-game Vsync settings today and realized that limiting the frame rate at 50% of my monitor refresh rate (60Hz) actually resulted in locking at 60 fps instead of 30 fps. Locking at 33% of my monitor refresh resulted in an effective frame locking at 30 fps (instead of the expected 20 fps). I’m using default settings in the Nvidia control panel.
Does anyone experience a similar behavior with a non Gsync/freesync monitor?
I just got finished flying and my MSFS vsync is working as advertised on my AMD based GPU.
Thanks for reporting. For some reasons, everything got back to normal tonight, without changing anything in the settings.
Sounds like another typical day running the sim! 
There’s definitely a couple of issues with VSYNC which appears to have been introduced recently. The issue highlighted being one of them.
My % of monitor is not working at all in-game. I have used NVCP to lock it instead now.