Are you talking about the standard DJI FC200 camera in the default DJI gimbal? If so, my camera centers at nearly parallel to the ground at start up.
If this is not the case for you, there might be something wrong with your gimbal, or perhaps just the gimbal settings in the Assistant app.
I might pop the rubber plug off the camera mount and check the servo screw... it may have loosened. Just tighten it carefully, and see if that helps. If not, break open the Assistant app and check the settings.