New Titan Slimline motor seizing

I realize that there is another post regarding a vibrating motor on the same page of this board, but that poster's solution had to do with his wiring and I am fairly certain that my wiring is fine as the cable was provided by e3d with the motor and I have been able to control the motor through other stepper output connections on the board with this cable.

I am installing a new Titan extruder with the e3d Titan Slimline motor (link). When I attempt a manual extrude command, the motor seizes/vibrates but will not turn. This new motor does 0.9° as opposed to the 1.8° motor I was using with the stock extruder. I have adjusted my steps/mm value to 837 as recommended by e3d.

I tested the motor on the Y-stepper output on the controller and was able to manually control it through Repetier just fine through that connection, so it appears that the motor is functional. I also tried reconnecting the previous stock extruder motor to E0 on the controller to make sure I hadn't fried that connection on the board, and it worked just fine as well, so I don't think I have burnt anything out.

Any suggestions? Could it be that the potentiometer is set too low/high for the new motor?

Thank you for the help!