Codex usage meter decreased unexpectedly while idle

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

26.623.141536

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Windows 11, x64

What issue are you seeing?

My Codex usage meter decreased unexpectedly while I was not actively running a Codex task.

I opened Codex and checked the remaining usage. The 5-hour usage window showed about 99% remaining. Shortly after, without submitting a new prompt, starting a task, editing files, or running any visible Codex operation, the remaining usage dropped to 94%.

I understand that usage accounting may be delayed, but from the UI it is unclear whether this decrease was caused by:

• delayed accounting from a previous task,
• a background Codex task,
• a usage meter refresh issue,
• or an unexpected model call while the app appeared idle.

There was no visible recent-usage detail explaining the 5% decrease.

Expected behavior:
The usage meter should only decrease when a Codex task/model call is actually running, or the UI should clearly show that the decrease is delayed accounting from a previous task.

Actual behavior:
The 5-hour usage remaining dropped from about 99% to 94% while the app appeared idle and no new visible task was started.

Environment:

• Product: Codex App / ChatGPT Codex
• Subscription: ChatGPT Plus
• Model shown in UI: GPT-5.5
• Reasoning level shown in UI: Extra High
• Access mode: Full Access
• Platform: Windows 11 x64

Additional context:
This may be delayed usage accounting rather than actual idle consumption. The main issue is that the UI does not make the source of the usage decrease visible to the user. It would be helpful if the usage UI showed recent usage entries with timestamp, model, reasoning level, and task/session source.

What steps can reproduce the bug?

1. Open Codex App / ChatGPT Codex.
2. Open the account usage menu and check the remaining Codex usage.
3. Observe that the 5-hour usage window shows about 99% remaining.
4. Do not submit a new prompt, start a task, edit files, run tests, or trigger any visible Codex operation.
5. Open the usage menu again shortly after.
6. Observe that the 5-hour usage remaining has dropped to about 94%.

I did not see any visible running task or recent usage entry explaining the decrease.

What is the expected behavior?

The usage meter should only decrease when a Codex task or model call is actually running.

If the decrease is caused by delayed accounting from a previous task, the UI should clearly indicate that and show recent usage details, such as timestamp, task/session source, model, reasoning level, and approximate usage amount.

Users should be able to understand why the quota changed.

Additional information

There appears to be at least one related issue: #31402. If this is considered a duplicate, please feel free to close it. I am mainly reporting that the UI does not expose enough information to distinguish delayed accounting from unexpected background usage.