Keep in mind when you're wiring your QuadFusion's motors to the Duet Maestro board which motor is connected to which port. The first picture in this guide labels each port as E0 Stepper, E1 Stepper, E2 External Driver, and E3 External Driver. When facing the front of your QuadFusion, the front left motor is 0, the front right motor is 2, the back left motor is 1, and the back right motor is 3.