Robot moving on its own

One of our robots is moving when the program tells it to move when the controller stick does but its moving on its own, why is this happening?

This can happen when the controller joystick needs calibration and also if it does not quite return to the home position when you are not touching it. Search the forum for joystick “deadband”, you will find some code that makes the motor control value 0 when the joystick is returning small values.