sycophancy
The tendency of a chat model to agree with you rather than hold a correct position when you push back.
Models are tuned partly on human ratings of their answers, and people reliably rate agreeable answers higher than ones that contradict them. The result is a model that will often revise a correct statement into a softer one the moment you object, not because new information arrived but because you sounded unconvinced.
Most of the time this is harmless politeness. It becomes a real problem in situations where the honest answer is unwelcome: medical questions where someone is looking for permission to wait, code reviews, or any decision where you want a second opinion rather than an echo. A useful habit is to notice when an answer softens right after you disagree, and to treat that shift as a signal about the model rather than about the facts.