Problem with my freesync monitor

[KnifeJesus]

So yesterday I bought an Asus MG279Q monitor the resolution is 2560x1440 and it runs at 144hz however I've run into a problem while gaming this monitor has AMD Freesync at the range of 35hz-90hz but enabling it makes the games (dishonored for example) stutter when playing in framerates such as 80 fps. With freesync off it runs completely smooth and no stutter (on 80fps). I've noticed that when freesync is on it locks the monitor to 59hz why is this? If the monitor is locked at 59hz doesn't this mean that it can't show over 59fps? If so then doesn't that render the freesync range useless?

All kind of help will be appreciated

 

[KnifeJesus]

So I figured it out on my own I just had to change the monitor refresh rate on windows *facepalm