Nate is right （full context can lead to a degradation of chats in several different ways） but you can't ask the AI about stuff like this as they have bad self-knowledge
A good approach is to compact the work so far （ask for a md file summarizing things） &； use it in the new chat
This is an interesting admission from Claude, and it's consistent with my experience with it. It gets more stubborn and attached as the context window gets long...