I found the reason [1] for the David Mayer case. It confused multiple David Mayers, one of them is a terrorist and is on a secret FBI watchlist [2] (often confused with another David Mayer, a theatre historian). ChatGPT confuses them with David Mayer de Rothschild as well, because it can't name Rothschild family members.
[1] https://x.com/igor_baikov/status/1863266663753285987
[2] https://www.theguardian.com/world/2018/dec/16/akhmed-one-arm...