Due to a municipal merger, there are currently two entries (or something else by a different name) for Salzkotten in OpenStreetMap. The larger one represents the current municipality, while the smaller one corresponds to the former municipality. In such cases, if both the old and new municipalities are linked to Wikidata, a display error can occur in the map on the Wikipedia article for the municipality (the error can no longer be reproduced, as I’ve already fixed it. I can provide an example later if I’m able to find one).