A software team has developed a customer service chatbot. During testing, they observe that the chatbot handles short, simple queries effectively. However, when engaged in extended, multi-turn conversations about a complex user issue, the chatbot frequently loses track of crucial details mentioned in the initial messages, leading to frustrated users and unresolved problems. Based on this observation, diagnose the most probable limitation of the chatbot's underlying model and propose a direct architectural strategy to mitigate this issue. Justify your reasoning.