Frederick Ferdinand of Anhalt-Köthen (25 June 1769, Pless – 23 August 1830, Köthen) was a German prince, Ascanian ruler of the principality of Anhalt-Pless and, from 1818, of the duchy of Anhalt-Köthen. He was the second son of Frederick Erdmann, Prince of Anhalt-Pless, and his wife, Louise Ferdinande, daughter of Henry Ernest, Count of Stolberg-Wernigerode.
Louise Ferdinand died in Pless.
It has Köthen after his death date, which indicates he died there. He was born in Pless. I don't think the AI understands the context of places of birth coming after dates.