The Dampers hold the gimbal to the Drone They are made of rubber and interestingly enough "unseat" rather easily.
examine carefully and make certain they are seated properly. what you are experiencing sure sounds like one or more of them may have...
"where" did you calibrate your IMU?? Outside, inside...ALSO take out your SD card and retry......yes really.ALSO the RUBBER DAMPERS make sure its all in place and correct....
It is a pain It IS supposed to work on both systems but when I use my MAC I have limited success and end up using the PC....some others say no problems, I would honestly find a PC to use.