ah thats because the new setup allow the AI to write a lot more, and the default memory limit is very small at 2k which means after 2-3 pages it will fill up the memory limit and forget about earlier pages faster. You should increase this memory limit by using your own AI (either with OpenRouter or setup local LLM).
You can also limit the AI output by reducing the max output from 1024 to maybe 256 to avoid the AI writing too much.