DIAGNOSIS The GamePlus crosshair feature has been activated and is persisting due to a software glitch or stuck hotkey.
FIX Press the monitor's joystick straight in to open the OSD. Navigate to GamePlus > Crosshair. Cycle through the options until you select "Off." Exit the OSD. If the crosshair remains, perform a full factory reset. While the monitor is on, press and hold the joystick for 10 seconds. The screen will go black and reset. Release the joystick. The crosshair will be cleared.
IF THAT DIDN'T WORK A third-party application like ASUS DisplayWidget Lite may be overriding the OSD settings. Close that application completely via Task Manager, then repeat the OSD steps.
HEADS UP The crosshair is rendered by the monitor's scalar, not the PC. It will appear over all inputs and even the OSD menu when active. It does not affect performance.