Codex Work large chats silently terminate after 7–30 seconds

Environment

• ChatGPT Codex desktop: 26.908.40834
• macOS: Golden Gate 27.0
• Hardware: Apple M3 Max, 36 GB RAM
• Execution target: Local, using local Git worktrees
• Permissions: Full access
• Model observed: GPT-5.6 Terra Light

Problem

Large Codex Work conversations begin processing and may edit files for 7–30 seconds, but then terminate silently with no response or visible error.

No approval request is pending. The integrated terminal and repository remain functional.

The issue reproduces in both the original conversation and a recovery conversation after fully quitting and restarting the macOS app. A brand-new small Local chat successfully completed a read-only repository inspection on the same Mac and network.

Expected behaviour

The turn should continue to completion or return a visible error explaining why execution stopped.

Diagnostic reference

Session ID:
01a04ada-4dae-7c73-9ebe-676ddb79966f

Approximate silent terminations in PDT / UTC−7:

• 2026-09-14 approximately 2:15 PM
• 2026-09-14 approximately 2:19 PM
• 2026-09-15 approximately 8:00 AM

The issue occurred repeatedly from approximately 2:00 PM September 14 through the morning of September 15.

Troubleshooting completed

• Confirmed no pending approval.
• Confirmed integrated terminal and Git repository work.
• Fully quit and restarted the desktop application.
• Reproduced in more than one large/recovery conversation.
• Confirmed a new small Local chat works normally.
• Submitted in-app diagnostic feedback with the session ID above.

Start by reproducing the silent termination in a large Local conversation on the macOS desktop app, using session ID 01a04ada-4dae-7c73-9ebe-676ddb79966f and the reported timestamps. Compare it with the successful small read-only chat and review the submitted diagnostic feedback; done means the turn completes or presents a visible error.