I don't know if this is your issue or not, but Windows updates has a habit of replacing specific monitor drivers from your manufacturer and replacing them with the Generic PNP. If you don't have a specific manufacturer supplied driver. Check on you manufacturers site and get one if it exist. If one doesn't exist, it likely works fine with the Generic PNP driver. I had to disable Windows 10 updates from downloading drivers to stop it from changing my monitor driver on me.
Also go to Device Manager and make sure the settings for your "Hz" aren't being limited there. Sometimes that gets set at 60 then the graphics driver doesn't pickup that 144 is available.