I think there may be a bug when creating or updating a plan mid-session.

I think there may be a bug when creating or updating a plan mid-session.

Sometimes, instead of updating the plan TODOs and asking me how I want to proceed, Copilot appears to repeat or surface an answer from an earlier prompt in the same session. This can be completely unrelated to the current plan request.

Expected behavior: when I ask Copilot to make or update a plan, it should update the TODOs / plan state and then ask me how to proceed.

Actual behavior: it sometimes returns an old response from a previous prompt, as if the session context or response state got mixed up.

---
| Field | Value |
| --- | --- |
| App version | 1.0.18 |
| OS | macOS 26.5.2 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Week 7 |

Start by reproducing the issue in the /chat flow on app version 1.0.18, focusing on creating or updating a plan after earlier prompts in the same session. Trace the session response and plan-state handling to identify why an earlier answer is surfaced; done means plan TODOs are updated and Copilot asks how to proceed instead.

索引モデルが issue の本文から書いたものです。