Yep. This is simply another case of the wrong tool for the job.
ChatGPT is designed from the foundations to be a chat application using the GPT model. It has all kinds of assorted tweakings and limitations to make it more specialized to chatty type uses (und thus correspondingly less suited to other, very different uses). The clue is right there in the name. It is not BookGPT or NovelistGPT.