First verify that IMU orientation is correctly set on GUI. Then perform motor configuration auto to get inverted status right and after set num.poles according the actual pole counts on the motors.
You most likely have inverted wrongly set for the motors.
the trouble with the auto pole process is that it thinks all three motors have different pole counts. Even though they are all the same type of motor ! What the heck ??
The inverter part works. The pole count is not that accurate. Set the pole count manually as per the real pole count for your motors, count the magnets if not known.
To me it looks on the video that the Gimbal is working ok, it is just not set up or tuned right. There is one axis that is not verified on video that it is balanced well, the Yaw. It needs to be well balanced too.
It could be just the PID and/or Power settings, but I think there is something else too. Did you verify the IMU directions before Auto motor configuration?
And as I always suggest, first get it working with one point calibration. I newer have needed anything else than one point calibration.
Ps. If you want to make better gimbal shorten the arms as much as possible. (of-course remaining balance)
Tried all the possible inversion combinations and the gimbal is as small as balancing will allow. just gonna scrap the thing, it's not worth the effort at this point. I got hours in to it with nothing back. Junk.
When it's powered off tilt the whole gimbal left and right, if the yaw is balanced the camera (lower part of the gimbal) will not move. If you tilt/lean to the left and the camera moves (rotates) to the left then you need to adjust the arm below the yaw motor towards you, if you tilt to the left and the camera moves to the right then slide the arm away from you. Do the adjustment about every 45 degrees in yaw for very fine tuning. Final result should be that when you lean/tilt in either direction the camera remains pointing directly ahead.