Nope. Not connection issue. Powering off and on will cause the emf/ back emf to colllapse. This will allow the motor to go back to the initial startup state before any overloading.
RC was running ok on first power up. Normally after running for a while or when hit obstacle it will go into the problem describe
Regardless. Will try a bigger C battery and get a programming card to see if the voltage cut off is set....