I have been reading the manual for your monitor..
You will need to use the display port cable to get 144hz, HDMI only goes to 60Hz..
From what i can see, you should have a disc for the monitor with the monitor driver on it.. It does say you will need the driver installed..
Also from the manual, you may have to use the OSD on the monitor to set to DP and overclock to a higher refresh rate..
Personally i would leave it at 144Hz and not OC..
AOC AG271QG 27 inch monitor | AOC Monitors | AOC Monitors
AMD Ryzen 9 9900x, Asus Prime X 9070, Asus Crosshair X870E Hero, 64gb Kingston DDR5 6000, Samsung 980pro 1tb NVME, Samsung 970 EVO Plus 1tb NVME, DeepCool Mystique 360 AIO, Antec Titanium 1000w.