Hello Laco

From OSM point of view that’s correct and Osm Nominatim search for administrative border but OsmAnd doesn’t do it. You can certainly see that from OsmAnd point of view it requires a lot of extra work to define all streets for administrative border and possibly it will be done in future for OsmAnd. That problem is common for projects that are not focused only on address data. From developer point of view address data is ugly designed in osm. However there are practices that simplify developer life. That’s address relations and OsmAnd supports it. Address relations (a3 - city, a6 - house) solves many problems :

  1. Combine different part of ways into 1 street (part of streets could have different tag name).
  2. Allows for one building has many addresses (if the building stays at street intersection it could have address from both streets and could be the same).
  3. Relations also do correspondance for city label and city border.