Further, this locked item on Eisenharz is not a common populated place, but the seat of a fourth-order administrative division, namely Argenbühl:
https://www.geonames.org/2931488/eisenharz.html
thanks I have deleted Argenbühl as ppl. Though the German postal office is using Argenbühl as a placename. I have added the postal code to the municipality to model this.