For the issue, please carefully do the Gyroscope/Accelerometer Calibration. Please double check that when you do the calibration, you do mount the gimbal absolutely the same way as the instruction shows, which is of great importance.
By the way, when you do it, please take out your camera from the gimbal first. Thanks.
You may also refer to the video below
Please watch the video from CH.5(about 18min30seconds).
And here is the tutorial of the calibration:
After that, please check the gimbal balance as follows：
To check the balance of roll and pitch, turn the gimbal off, and put it on the desk or ground:�If the pitch axis is balanced well when you move the camera, it can keep still in any direction.
If the roll axis is balanced well, when you turn the roll axis, the camera can keep still in any direction, with no wiggle or spinning.
To check the balance of yaw, turn the gimbal off and pick it up with your hand. Tilt 45 degrees and the camera can keep still, with no wiggle or spinning.
Looking forward to your response.