Disappearing Messages and Stability Problems

I’ve been working with ChatGPT 4o on a detailed framework, and the conversation has gotten pretty long. Once ChatGPT understands what needs to be done—processing the logic and writing the sections—it usually estimates about 1 to 3 hours for completion. The issue is that now it’s starting to break down.

When I ask for updates, it offers the option to review sections as they’re completed or wait for the entire thing. I opted for section-by-section reviews, and although ChatGPT said it wouldn’t stop its progress to send these, the problem is that the messages either disappear mid-typing or vanish after being sent.

I’ve saved the entire conversation as a PDF, which ended up at 899 pages. I’m trying to find a way to continue the project without losing the context and progress. Since the sections are interconnected, I need to ensure everything stays intact. Do you have any suggestions for how to resolve the disappearing message issue so I can keep things moving forward?