This is typically a refresh rate or adaptive sync conflict. Enable FreeSync and match your game's frame rate.
- Enable Radeon FreeSync™: In the monitor's OSD, go to Game Adjust and turn AMD FreeSync to On.
- Check Source Settings: On your PC, set the display refresh rate to 60Hz (the monitor's max via HDMI/DP is 3840x2160 at 60Hz).
- Use the Right Port: Connect your gaming PC using the DisplayPort (version 1.4) for the most stable high-bandwidth connection.
- Update Drivers: Update your graphics card drivers, especially if you have an AMD card, to ensure FreeSync compatibility.
IF THAT DIDN'T WORK: The flicker could be due to response time settings or HDR. In the OSD's Game Adjust menu, set Response Time to 'Normal' instead of 'Faster'. Also, try disabling HDR or Dynamic Action Sync in-game and in the OSD to see if the flickering stops.