That's interesting. Our Chinese friends have been caught cheating again. maybe they were getting too many complaints because it wasn't compatible with too many controllers. 12 magnet sensors seem to give a lot of problems for some reason.
OK, a couple of things I can think of. first of all, check that it's pulsing properly. connect it to the controller and measure the voltage between the signal wire and ground to see that it switches 5v on and off 6 times per rotation. Be careful that your motor doesn't start up unexpectedly. The second thing is to rotate it in the other direction to see if it works that way. maybe you had it in the wrong side of the BB.
When you put it back on the bike, check that you can see the middle bit rotating.