In case anyone wants to know, it was a bad tilt motor, I assume the feedback from the stepper was messed up, tilt and pan worked fine but it would jump buzz flicker ever few seconds.
Replaced gimbal motors and flex for a third time and all is good for now.
Mavic pro abnormal gimbal vibration with gimbal motor overload errors. Ribbon cable has been replaced, gimbal calibrates correctly but I still get the abnormal vibration. Seems to happen every 10 to 17 seconds. See video, how do I fix this? The video is of drone turned on only, just...