Can you tell me what LLM's are used?

I also have some concerns about the usage limits. In testing I had a couple of instances where the conversation dropped and the Ai wouldn't respond causing me to refresh and then it uses a conversation to pick back up where I left off. Is this a known issue? I'm just concerned it would cost me a lot of extra conversations just because the site dropped or glitched. Is there any way to avoid this issue?