Finalizing my mini p51 and went to test motor rotation and I think I have an ESC issue. Using a fresh bound x6r, throttle lead into port 1 and a tattu 3s-850 @ 3.8 volts to test and all I get is twitching??? I did try and calibrate the ESC via the usual throttle on high then plug the pack in. But am getting the same result. This the first time I've powered it up. Bad ESC?