Calibrate your ESCs with a parallel (6-way clone) Servo leads using an RC radio … there was a post on this in the past, IIRC the esc_calib code had to change the timeout for DJI motors … saw this in earlier firmware with t-motor ESCs … anyhow, sounds like ESC calibration issue …
That could indicate imbalance in yaw, e.g. sometimes people tilt the motors to get some more yaw authority. If not all motors are tilted correctly or by the same amount you can get such imbalances. It could of course also be related to ESC calibration or differences in propeller performance.
I would start with the ESC calibration as a first step.
@jfd - we did run ESC calibration and we are on the latest firmware, so I do not think this is the issue.
@tumbili - I think that’s it - some rotors tilt! We started with standard DJI F550 frame, but then replaced arms which we took from another similar frame. But the screws did not go in perfectly on some arms. So I suspect some arms have 1-2 degree tilt and that would explain the yaw generated.