Yes it is. Vsync allows FPS at only factors of the refresh rate in double buffered display contexts. 15/30/60 for 60hz, 18.75/37.5/75 for 75hz, 15/30/60/120 for 120hz and so on.
Just confirmed this on Elite Dangerous using native fullscreen. In an area where I would get ~45 FPS w/o vsync, I get 37 FPS with vsync because of my 75hz display. In an area where I would have ~60 FPS I get 37 for a bit... after a bit it does go up to 51, because the frame rate is swinging rapidly between 37 and 75 which is kinda nauseating. This is the whole reason gsync and freesync are things.
Setting an FPS limit at 60 for a 60hz display is not vsync.
Using full-window modes instead of exclusive fullscreen also kinda works around this by using triple buffering, but it introduces significantly more delay from input to display response.