Which connection are you using? If I recall correctly, only the dvi connection allows 144hz. You will need to go into amd catalyst, and go into one of the tabs for resolution, look for a custom resolution tab and force the refresh rate on your own. Lg Wh16ns40 Windows 10 Driver more. I had to do this on my tv.
I don't use an amd card anymore so I cant give you the exact tab names and steps, but once you get into the custom resolution tab, you should be able to enter your own refresh rate hz. Netgear Wpn111 Windows 10 Driver. If it fails (I don't think it will), then the screen will go black and stay black. When that happens, do NOT press any buttons. Just like any other time when it asks you if you'd like to keep that resolution with a countdown timer, you must let it run down and allow it to switch back on it's own.