Do you need to be on macOS 27 beta for the agents to work well in Xcode 27 beta? I tried using the agent yesterday in Xcode 27 beta on my Mac that isn't on macOS 27 beta yet (it's on 26.5.1) and it was very slow and just kept stopping without actually performing the steps. I did send a feedback. I was using a chat provider that is made available within our enterprise which provides access to many LLMs.