If you are using the GP-PRO with a Hero Session/Hero 5 Session, the first thing you'll want to check will be how you are mounting the camera. Often times users will insert the silver screw from the top which should be inserted from the bottom. If the silver screw is inserted from the top, this will cause vibrations. Here is a short video on how to mount your Session.
Please take a look at our other article "Gimbal Vibrations" for further troubleshooting tips with this issue.