Unofficial response: motor won't move forward, but will move backward

You probably have a broken motor controller. We had this happen in one of our cortex port’s motor controller, and also it happened to every motor controller plugged into our cortex in port 3… After some smoke.

this is because a motor controller is split into two parts, one MOSFET controls forwards and the other controls backwards. When a short circuit is created the active MOSFET would be the biggest load causing it to heat up and destroy itself