Separate Steering motor does not respond to servo signal

Hi, I am trying to adjust the rover, but the steering motor does not respond to the servo 1 signal. I set servo1_function = 26 and servo3_function = 70, when I operate it with the remote control, both servo outputs have values ​​and the throttle can run with RC. When I tested it with the motor test, the steering didn’t work, but the throttle worked fine. My steering motor is an MG995 and when I power it up alone, it responds instantly. Are there any other parameters that need to be set?

What controller do you use? Be aware that some Matek boards have no +5v middle pin on S1 and S2.

https://discuss.ardupilot.org/uploads/default/original/3X/c/5/c5f5a0f12473ddfe5d42c8d40d6802ffe769b654.jpeg

Thank you for your reply. I use ardupilot px4 to control the motors and provide 5V power to the motors alone. The throttle motor is the same way and works well. But the steering motor doesn’t run. So, I’m not sure if I need to set other parameters for steering.
https://ardupilot.org/rover/docs/rover-motor-and-servo-connections.html

I don’t think the motor test page is supposed to affect steering. It’s for the propulsion system.

The steering motor finally worked. I found the reason that I didn’t connect the power and ardupilot with the same ground. The ground or -wire has to be connected to the battery -, motor- and Cube servo -pin.