DIAGNOSIS The monitor is likely in a default preset like Standard or User mode with low saturation. The IPS panel's native color needs proper configuration.
FIX Press the menu button. Go to Picture. Set Picture Mode to 'Graphics' or 'Movie'. These presets boost color saturation. Then, navigate to Color. Set Color Temperature to 'Warm' or 'User' and adjust the Red/Green/Blue gains. Start with R:100, G:98, B:100.
IF THAT DIDN'T WORK The issue could be in Windows. Right-click desktop, select Display Settings. Ensure HDR is off for this monitor. Then go to Graphics Settings and ensure color profile isn't overridden. Also check your GPU control panel (Nvidia Control Panel or AMD Adrenalin) for output dynamic range settings; set to Full.
HEADS UP The 99% sRGB claim is for a calibrated profile. Out of the box, the default settings are often conservative. It will not look as vibrant as a VA panel without adjustment.