The article says that Grok is "writing that Hitler served as “Führer und Reichskanzler from August 1934 until his suicide in 1945."
Wikipedia page on Hitler says that he "took the title of Führer und Reichskanzler in 1934".
What is tendencious about either? It is right to report the titles in German, not least because Hitler is known for his title "Führer" pretty much universally so that it is an important keyword to include. It does not imply anything.
This all sounds like trying too hard to find "dirt", frankly.
Wikipedia page on Hitler says that he "took the title of Führer und Reichskanzler in 1934".
What is tendencious about either? It is right to report the titles in German, not least because Hitler is known for his title "Führer" pretty much universally so that it is an important keyword to include. It does not imply anything.
This all sounds like trying too hard to find "dirt", frankly.