I had two similar issues. Found that by shaking the tx the heli would jump and twitch. That was after I had tried to find the glitch elsewhere. A simple tightening of the antenna in the tx by screwing it in fixed the big problem. Smaller glitches were interference that a DX7 radio took care of. I had a need for new radio so I got the DX7 and swapped out the rx in the cp pro.

Also, take the back off the tx and look for loose antenna leads inside the radio.

Good luck