Servos are not responding to transmitter signals

Hello everyone.
I need some advice regarding my Pixhawk PX4 autopilot. After connecting the servos through the Holybro PM07 board, the servos are not responding to signals from the transmitter. I am powering the servos separately through a BEC, which is also connected to the motor. The PPM module is transmitting signals through QGroundControl, but the servos are not responding beyond that. I can only control them through the servo test in QGroundControl. I have deactivated all safety commands. Could anyone advise me on how to proceed with this issue?
Thank you for your help.