Gemini 1.5 Pro, however, fumbles the ball! Maybe the takeaway is that questions like this could be good for differentiating between specific chatbots, but don't tell us anything intrinsic about how LLMs work in general.

I tried this on Claude, and it too produced a correct, well-explained answer.

What version of ChatGPT did you test? I just tried your exact prompt with 4o, and got what looks like a perfect (and well-explained) result. (or am I misreading?)