There where some recent fixes in the software of Nominatim and the OSM data to ensure that state cities like Hamburg are matched correctly against their boundaries. You need at least Nomiantim Nominatim 3.5.0 and OSM data from April 2020 or later to make this work correctly on your server.

There where some recent fixes in the software of Nominatim and the OSM data to ensure that state cities like Hamburg are matched correctly against their boundaries. You need at least Nomiantim 3.5.0 and OSM data from April 2020 or later to make this work correctly on your server.