ChatGPT is not particularly good at coming up with new jokes, because often the process of creating a joke is non-linear. You usually think of the punch line first, then come up with the setup afterwards.

ChatGPT responses are constructed in a linear fashion, and it is not capable of this type of non-linear thinking. Considering this, I'd say that ChatGPT does not have a sense of humor. It can explain jokes right now, but is not good at coming up with new ones.

That said, I'm sure this problem is being worked on and there's a good chance in a few years that this will be possible. This line of research, I'm sure, will help with far more than just humor.