Before calibrating your monitor via Palette Master Ultimate (PMU), it is recommended you turn off the following macOS settings to obtain the best calibration results:
Configuration path: Apple menu > System Settings or System Preferences > Display
1. Turn off “True Tone”
2. Turn off “HDR” (High Dynamic Range)
3. Turn off "Mirror Display mode"
4. Turn off "Night Shift"
5. Turn off “Automatically adjust brightness”