The railroad tracks show as an overpass, so it is asking about that.  It is asking about the way under the overpass, but the way OSM works, is it looks at the entire way (or segment of road), even the part not directly under it.  Best way to do it in the future for segments with intersections  close to the underpass is to split the way at those intersections (on the underpass side) and then add the height appropriately.

Or just add the bridge maxheight to the way, even if it isn't directly above.