Kyle,
I had the same problem. In my case it was the throttle trim. The throttle needs to off during binding otherwise, as I understand, the system simply disables the throttle. If there is any trim set, the system thinks there is positive throttle and doesn't allow use of the throttle.

I subsequently ran into the same problem on the Blade 400, and solved it instantly by adjusting the trim to neutral, disconnecting the helicopter battery and reconnecting it.

I recommend you use the airplane setup for the mCX and then binding is dead simple.

Hope this solves your problem.