I’ve had Claude opus do that too.

I had a totally benign chat with OpenAI and it titled it as “amateur porn” in Chinese characters, it was very alarmed when I pointed the conversation name out to it. It almost never misses these days, but when it does the failure modes are very strange.

Got Russian from it once. As a child of the '80s I jumped right on it, but the explanation seemed believable.

Still sleeping with one eye open.

A Hindi word in the middle of a normal reply for me (but once I translated the word it was right in context heh)