[DrKnow65]

Cham, I had to use an external BEC with my MMM and a single high speed servo, so you may very well have a low voltage issue. My system acted differently though, it would just shut down my receiver and the MMM would re-arm.

It sounds to me more likely that you have some radio frequency interference happening. Make sure that none of your servo wires or antenna are too close/parallel to the motor wires. Try unplugging the motor wires, does the problem go away? Are any of the servo wires pinched and making a circuit with the chassis? Does it run a single servo and the motor OK? Does it run just the MMM and motor OK? Any chance you can add a capacitor to smooth the voltage to the radio?

Also make sure that all the connectors are the right way in the receiver (I.e. The ground/black or brown wires of the servos are all twards the outside edge on the rx).