If you're looking for advice in a situation where you are not sure of what the correct choices are, you will find LLM chat AI to go in circles. It says one thing. Something is dodgy about it, so you raise a tentative objection (as a non-expert). The thing does a "you are completely right, I apologize" about face and then says something different, and things have begun to slide into uncertainty.
That might not exactly be sycophancy, but it's basically the same thing: producing responses that are reflection of what is in the chat, rather than any real shit.
Pick any topic where people disagree. It could be an entirely technical topic in which engineers have settled the questions, and the only contrarians are crackpots. The problem is that the crackpots are out there writing, and this is snarfed into the training data. Crackpots use certain ways of talking about certain subjects. If you use similar vocabulary and concepts that align with some crackpot theory, the AI simply starts predicting tokens according to that, and you are now in crackpot land: what you are saying is validated using the crackpot terms. Next, write in a way that reintroduces rigidity: proper terminology and correct concepts, and, whoa, the AI is an engineer again, contradicting the previous crackpot shit.