Vehicle did not respond to Custom Command

Hi everyone!
I am currently implementing a button for arming and other for disarming the motors using Custom Command Widget.
I established the connection with Parameter Protocol, so the information of my QML buttons is displayed correctly.
On click, each button sends a command long number 400: MAV_CMD_COMPONENT_ARM_DISARM and i am sure that the Command long handler is accessed correctly after pressing one of each buttons.
Though, an error message appears on my QGC saying that Vehicle did not respond to command: Arm/Disarm.
Why is this happening?

Any progress made on this?