Motor spins much faster when they armed by mavros

Hi guys, I have experienced weird situation.
Before start, my settings are:

Pixhawk4 with PX4 FMU V5
NVIDIA Jetson TX2 Development kit
Communication by serial port(TX2) to TELEM2 port according to

When I arm the motor with RC in MANUAL mode, motor spins at PWM_MIN, which is very natural result.
However, when I arm the motor with MAVROS in OFFBOARD mode, motor does not spin at PWM_MIN. It seems to spin much faster than armed by RC.

Is it natural? I’m not sure whether it is safe to equip propeller to the motor in this situation.

I’m not too familiar with offboard mode, but it could be that offboard mode is considered an auto mode, in which case the parameter MPC_THR_MIN dictates the minimum thrust, rather than MPC_MANTHR_MIN as in manual mode.