[App 26.825.51511] Cross-task delegated prompt can be ignored in favor of stale task context

What version of the Codex App are you using (From “About Codex” dialog)?

Codex App 26.825.51511, build 7377.

What subscription do you have?

ChatGPT paid plan. The exact tier is omitted because the failure appears unrelated to plan limits.

What platform is your computer?

Darwin 25.6.0 arm64 arm (macOS 26.6.2, build 25G83).

What issue are you seeing?

A prompt delivered from another Codex task can be visibly accepted in the target task but fail to become the authoritative active context for the next user message.

In the observed case, the target task had already completed an unrelated hotfix. Another task then sent it a new, unrelated assignment through cross-task messaging. The new prompt appeared correctly in the transcript with the label Sent by ChatGPT from another task and its delegated turn completed.

The user then sent a short follow-up that clearly referred to the delegated assignment. Instead of continuing that assignment, the agent recovered the stale pre-delegation context, inspected the already completed hotfix again, and answered about that old work.

This has now happened twice with the same cross-task workflow. The transcript visibly contains the new delegated prompt, so this looks like an active-context or compaction/continuation-selection failure rather than a rendering problem.

The impact is more than a confusing answer: the agent can inspect the wrong repository state or perform authorized actions against the wrong task because it believes an already completed assignment is current.

Project names, task numbers, local paths, and full prompts are omitted. A privacy-redacted screenshot is available if maintainers need it.

What steps can reproduce the bug?

1. Complete an ordinary task in Codex Desktop and leave that task idle.
2. From a different Codex task, use cross-task messaging to send the completed target task a new assignment unrelated to its previous work.
3. Confirm that the target transcript shows the message labeled Sent by ChatGPT from another task.
4. Let the delegated turn run or complete.
5. In the target task, send a short direct follow-up whose referent is unambiguous only in the delegated assignment, for example: “Before closing, remember to leave the reviewer a comment.”
6. Observe that the agent may resolve the follow-up against the target task's stale pre-delegation context and resume the already completed work instead of the newly delegated assignment.

The failure is intermittent but has occurred twice in real use.

What is the expected behavior?

The newest cross-task delegated prompt must become the authoritative active request in the receiving task. Subsequent direct user messages should continue that delegated context unless the user explicitly replaces it.

If the app/model cannot determine which task a short follow-up refers to, it should ask for clarification rather than silently resume stale completed work.

A regression test should cover a receiving task with substantial completed history, a new unrelated cross-task prompt, compaction or summary restoration, and a short direct follow-up after the delegated turn.

Additional information

• The delegated-message marker itself rendered correctly.
• This is distinct from display/disclosure issues such as #41430 and relationship-navigation proposals such as #40270.
• No private session IDs, task IDs, repository paths, or raw rollout data are included.
• The issue was observed on 1 September 2026 in the Europe/Moscow time zone.

Start with the cross-task messaging entry point and the compaction or summary-restoration path described in the reproduction steps. Reproduce a completed receiving task, send it an unrelated delegated prompt, then issue a short follow-up; done means the follow-up stays in the delegated context and a regression test covers this sequence.