Understanding Conversation Size Limits and Context Window Issues in Dust with SharePoint Queries

Hello team, I am hitting conversation size limit in the very first message. Does anybody know what may cause this? (The underlying LLM should have 256k if not 1M context window. This is a simple sharepoint retrieval query) The feeling of not being able to use Dust beyond toy/demo examples is slightly growing around with the new pricing and limitations, I am not sure what is happening Thanks