I've had this monitor for over a year now and this has never happened to me. I noticed that now when I set the monitor to 144hz or 120hz the screen starts to flash/flicker. I have made sure all my drivers are up to date and I have also reset my computer and changed multiple HDMI coords.
This is what it looks like-View: https://www.youtube.com/watch?v=whWPc37kbqA
This is what it looks like-