ESC Calibration Output PWM Min/Max reset all the time

Is it possible that there is nan issue with this settings ?
Default they are
Output PWM Min=1000 and
Output PWM Max = 2000.
If the values be edited to something else lets say 1050 / 1950 after reconnect with missionplanner they go back to default.
Is it also po9ssible that this affect they Head room calculation ?