As per research, "Generalagentur Manfred Lennertz / Allfinanz Deutsche Vermögensberatung" is housenumber 8, and is marked on the there provided map as the house on the corner. https://www.allfinanz-dvag.de/manfred.lennertz/ueber-uns.html 
Maybe housenumber 6 and 8 do share the same entry (as other building in that area do) ?

