I'm an accountant, and when someone asks me about the rash on their skin I say, 'I'm not a doctor, I'm an accountant'.
When you ask ChatGPT something that is not it's job it just bullshits its way through like a cheap salesman.
It's not like your asking a singular person the question like it is when you ask an accountant but an abstraction of written human thought and interactions.
It seems to me that it has a problem with questions about incidence structures, scenarios where objects of type X are just lists of incident objects from set Y, and objects from set Y are just lists of incident objects from set X. A station is just a list of all the services which go there, a service is just a list of all the stations it goes to. A product line is just a list of products, each product is part of some product lines. A geometrical line is just a co-linear set of points, a geometrical point is just the intersection of several lines.
Conjecture: any time you ask it questions which involve reasoning about an incidence structure, it will either hallucinate incidences that aren't or neglect incidences that are. The logic of incidence is lost on it, the answers it gives are inconsistent and contradictory.
I asked to to summarize an online article, and it fabricated an author's name, despite the line "Author: [author name and firm]" being right under the top.
I then challenged it, and it apologized for the confusion and error, then fabricated a different author's name. And a wrong date of publication, which was also listed. It eventually got the date right, but continued fabricating names until I gave up laughing. Even after I told it to look on the line beginning with "Author". Odd thing was, it threw an error when I told it about "Author: FName", as if it freaked out when asked to tell a fact. But then it just fabricated another with "FName Fabrication#8"...
Actively, cheerfully, malicious...
So I asked it what products does our brand make and it listed 5 products in the smaller selling product range of our 2.
I asked about the bigger product range and it listed one of them and then made up several other products that don't exist! It even gave details of what they (don't) do.
One of those sounds like something that should go in our roadmap...