I noticed that same behavior across older Gemini models. I build a chatbot at work around 1.5 Flash, and one day suddenly it was behaving like that. it was perfect before, but after it always saluted the user like it was their first chat, despite me sending the history. And i didn't found any changelog regarding that at the time.
After that i moved to OpenAI, Gemini models just seem unreliable on that regard.
This might be because Gemini silently updates checkpoints (1.5 001 -> 1.5 002, 2.5 0325 -> 2.5 0506 -> 2.5 0605) while OpenAI doesn't update them without ensuring that they're uniformly better and typically emails customers when they are updated.
85392_school|9 months ago