DJI Mavic Pro Gimbal Calibration after latest firmware upgrade installed OK and everthing including batteries updated.
Calibrated IMU OK

Tried to calibrate gimbal gets to 77% and no further   

After 5-6 failed attempts reset all gimbal settings to factory default


Tried again result the same gets to 77% and no further

Anyone else had similar problems and managed to find a fix?

When you turn on the aircraft, will the gimbal calibrate itself automatically?
Did you get any gimbal error message from DJI GO app?

I found a fix for this issue.  I place the aircraft on a mat or piece of paper that can slide on the ground easily, when the calibration gets stuck at 77%, I very slowly rotate the aircraft clockwise (barely).  This unsticks the calibration and allows it to continue.

I'm not entirely sure if this is a software or hardware issue with the mavic, but I am waiting to hear back from DJI.

I fixed my gimbal not calibrating problem with 2 steps.  I used a different battery on the drone.  Maybe my first battery wasn't updated?  I also flew the drone a few times without the clear globe over the gimbal to minimize glare.  I landed today in very dry/fine dirt and made a cloud when landing.  I used a q-tip to clean as much dirt/dust as I could without forcing anything.  My first attempt at calibration was successful after countless failed attempts this afternoon.  Maybe one of these 2 options may be a solution for you.  I don't see me flying without the cover anymore...