I have been flying with 1.8.8 and was having terrible trouble with my gimbal making smooth, level adjustments when I turned the aircraft. I was okay when taking photos because I can easily level the horizon in Lightroom. But filming while slowly panning was terrible as my horizons would tilt miserably. I've had a ticket open with DJI for the past week, they suggested I upgrade to 1.9.6, link my RC, perform a IMU and then a gimbal calibration. I have done every type of gimbal calibration with no success and have done several cool, level IMU calibrations with no success. I really didn't think this would help because when I read what the 1.9 firmware addresses, it says nothing about gimbals.
Well, I did what they requested and just took my bird out to fly. I did several hard turns and generally put her thru the ringer and my gimbal was steady as a rock! I can't believe it! I'm going to test her tomorrow but I've got my fingers crossed. I know a lot of pilots are having tilted horizon problems so I wanted to share my story. Going to 1.9.60 was a necessity for me.