If some of you confirm the bug, I would open a bug report.
If your OpenAPI spec uses enum type in its properties, GPT won’t actually honor the definitions. Sometimes, it would make up a value outside the enum definitions.
That would cause a lot of frustration for your users because it is a hit-and-miss.
GPT’s ability to choose the right endpoint has degraded too. How do I know that? After I ask ChatGPT why it chooses a particular endpoint, it would admit it has made a mistake.