Die Leute von OSMand haben das geantwortet:

Hello,
 
We downloaded a map of Saxony and checked this information.
The search works correctly, only the address Rathenaustraße, 5 does not belong to Zschortau, but to Rackwitz, which can be seen from the OSM addr:city relation, which uses the Nominatim algorithm.
You can find details about Address Search here:
https://osmand.net/docs/user/search/search-address
 
Regards,