Take a look at the gps track. Are you wearing the watch on your right wrist? try left. The difference is exaggerated because of reflections/geometry.
It turns out that the extra distance in lane 6 is 8% assuming standard lane widths.
I'll try the other wrist. My arm, however, was not long enough to stretch over to lane 6.
Maybe if you mount it on a selfie stick?
Maybe I'll just run in the other direction.