DIAGNOSIS You probably didn't get a bad panel. The ProArt comes factory-calibrated, but your computer's graphics driver might be overriding those settings with a default color profile or incorrect output range.
FIX First, let's check the monitor's own settings. Use the joystick to open the OSD. Go to the 'Color' menu. Ensure the 'Color Temperature' is set to '6500K' and the 'Gamma' is set to '2.2'. Most importantly, make sure 'Adaptive-Sync' is Off for color-critical work, as it can affect gamma. Next, on your Windows PC, right-click the desktop and select 'Display settings'. Click 'Advanced display' and then 'Display adapter properties'. In the new window, go to the 'Color Management' tab. Click 'Color Management...', then the 'Advanced' tab, and ensure 'Windows Color System' is the default. Don't load any .icc profiles here unless you've created one yourself.
IF THAT DIDN'T WORK The issue is likely the output dynamic range from your GPU. In your NVIDIA Control Panel or AMD Radeon Settings, under 'Display' > 'Change resolution', look for an option like 'Output dynamic range' and set it to 'Full' instead of 'Limited'.
HEADS UP The ProArt's 'Splendid' presets (like sRGB, Rec.709) lock certain color settings. If you need to adjust brightness or color space, use the 'User Mode' preset for full control.