When an unread Codex session opens, it should land on the last user message.
That message is the start of the newest assistant reply, so the user can read the new answer from the beginning.
A stable rule could be:
- unread session: open at the last user prompt
-
- read session: restore the previous scroll position
- This would make unread sessions much easier to review, especially for long replies.
I found a related thread about conversations becoming unread after restart, and this request is specifically about the opening scroll position for unread sessions.