The new 3in1 will need some adjustment. Look at the manual to help. I would suggest that the next time the 3N1 goes bad, you spend the money on a heading hold gyro, and 2 separate ESCs to control the 2 motors. I went through several 3n1s and finally gave up and went separates. The servo jumping is kind of strange. If it's moving alot, then I wonder if your receiver or servo is bad. I would try replacing the servo first since they just sent you a new receiver. If when you move the cyclic the servo movement is erratic than I would suspect the servo is shot. It is also possible you are getting interference on your receiver from some other source, but I would suspect the servo first.