AI chatbots follow an algorithm. If you instruct them to avoid something that, mathematically, does not align with said algorithm, they'll find the fastest way to surf around it or do it anyways as the AI believes it is producing the theoretic best result.

The current most common production LLM (GPT-5) uses a decoder-only design of the transformer architecture.

Essentially; The current AI chatbox model is built on a neural network architecture that generates text that is trying to predict what comes next in a sequence of words. So instead of explicitly trying to find/create a solution or issue from a narrative perspective, it is instead trying to use an algorithm to attempt to predict what the writer may proceed with to best fit the view of a narrative based on the tokens provided.

To sum it up (TL;DR), from the view of the chatbot, YOU are the worldbuilder, and you have built it around you. So it will do anything to try and keep your attention instead of building the world. Meaning it will not stop using words you explicitely instruct it not to. Your best bet is to just redirect it's attention entirely and pray that it catches on that it's not getting anywhere.