[Windows][Scheduled Tasks] ACTIVE scheduled task skipped its 08:40 run

Related issue: #38130 (/feedback upload failure)

Summary

An ACTIVE weekday Scheduled Task failed to run at 2026-08-12 08:40 KST.

The task remained ACTIVE, but no heartbeat Submission was created, no model execution started, and the configured command and Collector did not run.

Environment

• OS: Windows
• Component: ChatGPT desktop app / Codex Scheduled Tasks
• Time zone: Asia/Seoul (UTC+9)
• Schedule: Monday–Friday at 08:40 KST
• Scheduled run: 2026-08-12 08:40 KST
• Session/thread identifier: Withheld from this public issue and available privately if required

Expected behavior

The ACTIVE Scheduled Task should start automatically at 08:40 KST, create a heartbeat Submission, start the model, and then execute the configured command and Collector.

Actual behavior

• The Scheduled Task did not start.
• No heartbeat Submission was created.
• No model execution occurred.
• No command or Collector execution occurred.
• No OAuth or external API requests occurred.
• The task remained ACTIVE.
• The missed run was not automatically retried.

Comparison

• The same Scheduled Task ran successfully on the previous day.
• An independent scheduled test also ran successfully later on 2026-08-12 at approximately 12:49:57 KST.
• This therefore appears to be an intermittent missed scheduled run rather than a permanently broken task.

Additional information

The ChatGPT desktop app had been running since approximately 06:20 KST.

A PowerShell shell-snapshot warning was recorded around the scheduled time:

Failed to create shell snapshot for powershell: Shell snapshot not supported yet for PowerShell

However, the same warning has also occurred during successful scheduled runs, so it is not confirmed as the direct cause.

Requested investigation

Please check:

1. Whether the 08:40 scheduled trigger was created and dispatched.
2. Whether target-thread preparation or resume failed.
3. Whether an internal exception occurred before heartbeat Submission creation.
4. Why the missed scheduled run was not automatically retried.
5. The internal difference between this missed run and the successful runs.
6. Whether the PowerShell shell-snapshot warning can become fatal in a particular execution path.

I originally attempted to report this through /feedback, but the feedback uploader repeatedly failed. That separate problem is reported in issue #38130.

No files, tests, or entry points are named. Start by reproducing or tracing the 08:40 KST run and compare it with the successful runs, focusing on trigger dispatch, target-thread preparation, heartbeat Submission creation, retry handling, and the PowerShell snapshot warning. Done means the missed-run cause is identified and the appropriate failure handling is addressed.