In SITL, the speed of the fixed-wing FBWB does not change according to the parameters

In Mission Planner SITL for fixed-wing aircraft, speed control using parameters does not work in FBWB mode. Can you tell me why?
The maximum speed is fixed at 27 and the minimum speed at 20, and the speed does not change even if the values are changed.
Here are my current settings.
AIRSPEED_CRUISE 22
AIRSPEED_MAX 27
AIRSPEED_MIN 18