Hey Douglas,
that a malfunction of the machine could be caused by your smartphone is extremely unlikely.
However, a fault in which the stepper motor runs in the wrong direction is practically always a cable problem. As the connectors are the weak spot of this machine, this is seen frequently, e.g. like in this case.
The connectors (not the controller) are the weak spot on this machine, especially combined with the lack of strain relief on this machine. That’s why I would first check what is described in this FAQ document under point 3). This is the most common cause of such problems.