[Windows] Completed Codex task disappears from sidebar and task search while remaining recoverable by internal task ID

No source files or tests are named. Start by tracing how completed tasks are persisted, indexed, and loaded into the Windows sidebar and task search, using task ID 019f878f-54dd-7c43-8b6a-f18f511f8f4d as a reference. Done means a completed task remains visible and searchable whenever its transcript and metadata still exist.

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

OpenAI.Codex_26.623.13972.0_x64__2p2nqsd0c76g0

What subscription do you have?

ChatGPT Pro (5×)

What platform is your computer?

Microsoft Windows NT 10.0.xxxxx.x x64

What issue are you seeing?

I have encountered a recurring issue where completed Codex tasks disappear from both the sidebar and the searchable task list, even though the underlying conversation still exists.

In the most recent occurrence:

• Task ID: 019f878f-54dd-7c43-8b6a-f18f511f8f4d
• Started: 2026-07-21 approximately 22:02
• Completed: 2026-07-22 approximately 02:33

The task is no longer visible in the sidebar.
It is also absent from the searchable task index.
However, the task itself still exists:

• the transcript is intact,
• metadata (title, timestamps, task ID) is preserved,
• generated project artifacts remain available,
• the conversation can still be recovered by directly referencing the internal task ID.

This suggests that the conversation data was not deleted, but that the task became detached from whatever index populates the sidebar and search.
This has happened multiple times, particularly with long-running project tasks.
No explicit error message was displayed. The task simply disappeared from the UI after completion.

What steps can reproduce the bug?

Unfortunately I do not yet have deterministic reproduction steps.
The issue has occurred multiple times during long-running Codex project sessions.

What is the expected behavior?

Completed tasks should remain visible in the project sidebar and searchable through the task index.
If the underlying conversation still exists, the sidebar and search index should remain consistent with the stored task.
Tasks should not become "orphaned," where the transcript is preserved but the UI no longer references it.

Additional information

Additional observations:

• This does not appear to be data loss.
• The transcript, metadata, and generated artifacts remain intact.
• The issue appears to affect discoverability rather than storage.
• The missing task was recoverable by directly referencing its internal task ID.

My suspicion is that this is related to indexing, synchronization, or sidebar state rather than deletion.