darker portion on the display

This issue is usually related to the display panel or refresh rate handling. Uneven darker areas at 144Hz and low brightness often indicate panel uniformity issues or backlight/PWM behavior. Try updating your graphics drivers and adjusting settings like adaptive sync or color profiles. Test different refresh rates and brightness levels to confirm the pattern. If the issue disappears at 60Hz, it could be a panel limitation or hardware defect. Also check if any display calibration software is interfering. If the problem persists, the screen itself may be degrading, and panel replacement might be required for a permanent fix.