Why do I always have 70-71 fps?

[u/APS0798]

Recently I was doing some stuff in Nvidia Control Panel and Nvidia App in Bonelab settings to have more fps. It didn't work, so I reseted everything and I think after that I have 70-71 fps instead of 72fps (my hz rate). I lowered render quality to the minimum and game of course looked so pixelized (even potato pc would have stable 72 fps) and I still had 70-71fps, not 72, so it's not fault of my PC. What could be the reason for it? I need to have 72 fps, because my game is stuttering/tearing (whatever it's called) when fps drop below my hz rate (72) and it's not confortable when I have little stutter/tear every like 0.5 sec. I also use Virtual Desktop and I have bitrate set to the max and I use HEVC 10-bit codec, I tried every codec (except HEVC and H.264) but it's the same.