Hello everyone again, my friend got an acer ek241y. At first he used a rx 580 and the monitor was running at 75hz. It was fine in desktop with some weird artifacts like and screen flickering and lines or flashing during ingames. Those happened very very fast and brief like within a second. So he thought it was the gpu that's faulty. Today, he swapped it out with a gtx 1660 super. Ran ddu and uninstall the old drivers etc. Now after finish installing nvidia graphic drivers, the monitor straight glitches out. There were lines everywhere and flickering nonstop even in desktop. But when he switch to 60hz, everything is okay. He tried different hdmi cables, same result. I've searched around the forums and it seems to be related to cheap ips monitor having this issue. Any other ideas?