I use chromadb and gpt3 summaries to manage the conversation history and assemble a unique message list for each exchange that points everything in the right direction. This message list is tuned to get gpt4 to give the best response possible. What you see in the chat is your message and the replies, but the actual conversation is different. Keeps the conversation focused and in the context window, works great.
(You case sounds like maybe the outputs aren’t making it over?) The assistats api isn’t bulletproof for sure but it does work with relative consistency for me. If it bombs out now and again I figure it’s the api, but if it’s constantly failing it’s probably me.