I have edited my gmapping node to always publish zero transform from map to odom (reason being that map -- > odom keeps violently changing when I spin my lidar which causes the robot to jump around in rviz). Now when i start gmapping, everything works fine, but after some time, as I move my robot using teleop, I see the scan lines of lidar are displaced from the actual lidar frame as it shows in rviz. Means, the lidar frame and all other frames are in their proper place relative to base_link as appears in rviz, but the origin of scan lines (which make up the map) appear to be somewhere else, not on the lidar's frame.

Any ideas on why the origin of scan lines is displaced from their actual origin ? Thanks