I had a brand new in box N3 and LB2 system sitting around forever so I decided to install them into a Y6 900mm RCtimer frame. Propulsion is from T-motor 4109's and T-motor 30A esc's.
I have updated everything to the latest firmware using the associated Assistants. Compass and IMU calibrations have also been done. No warnings showing on the DJI GO app when connected.
The problem I am seeing is that I either have partial or no yaw control most of the time. I have calibrated the DJI Remote controller using the Go app.
While the bird is hovering, if I give it a yaw command nothing happens at any stick position. If I continue to hold a yaw command it may start yawing after about 20 seconds and then continues to yaw even after centering the stick. The flight gets a bit erratic from that point on so I land and disarm it.
Once in a blue moon if I disarm and then arm and try again I may have good yaw authority for about 30 seconds and then it slowly quits responding to my inputs.
I have tried calibrating the esc's with the Assistant for Autopilot and it seemed to work correctly.
The bird hovers excellently and pitch and roll work spot on.
I have tried adjusting the yaw gain in 10% increments with no difference.
Does anybody have suggestions?

DJI, any comments?