I had a similar experience earlier. Described a problem that isn't even that hard - very similar to something there are probably lots of examples of online but subtly different. I wanted to see if handled these subtly different requirements.
It failed miserably, even with repeated instructions. It just assumed I wanted the more common problem. Every time I pointed out the problem it would say "sorry for the confusion, I've fixed it now" and give me back identical code. I even asked it to talk me through test cases. It identified that its own code didn't pass the test cases but then still gave me back identical code.
I’ve found persistence is not a good strategy with GPT. Put effort into your prompt, maybe try clarifying once, and if it doesn’t work, do not keep trying. It will get closer to the solution at a diminishing rate, just enough to tease you along, never getting there.
It failed miserably, even with repeated instructions. It just assumed I wanted the more common problem. Every time I pointed out the problem it would say "sorry for the confusion, I've fixed it now" and give me back identical code. I even asked it to talk me through test cases. It identified that its own code didn't pass the test cases but then still gave me back identical code.
I eventually gave up.