Windows Desktop: enabling workspace-write network access causes progressive UI lag and long Settings/session-switch spinners

Reproduce the Windows 11 A/B comparison with workspace-write and Allow network access enabled, then inspect the Windows network-sandbox initialization or reconciliation path. Use config.toml's network_access setting and Windows Application Error Event ID 1000 as the comparison signals. Done means network access no longer causes progressive UI lag, long Settings or conversation-switch spinners, or repeated process exceptions.

Codex App version

OpenAI.Codex_26.707.12708.0_x64 (Microsoft Store)

Platform

Windows 11 x64

What happened?

On Codex Desktop for Windows, the app becomes progressively sluggish when using the workspace-write sandbox with Allow network access enabled.

Symptoms:

• Switching conversations becomes increasingly slow.
• Opening Settings shows a spinner for a long time.
• The UI gets worse the longer the app remains open.
• Disabling MCP servers did not resolve the issue.

Controlled A/B result

With the same account, workspace, and application build:

1. Set sandbox mode to workspace-write.
2. Enable Allow network access.
3. Use Codex normally and switch conversations or open Settings.
4. Progressive UI lag and long spinners appear.

Then:

1. Disable Allow network access.
2. config.toml changes to network_access = "restricted".
3. Restart Codex and repeat the same actions.

Result: the lag disappears completely.

Event-log correlation

Before disabling network access, an affected Codex process produced 20 Windows Application Error events in about four minutes:

• Application: ChatGPT.exe
• Event ID: 1000
• Exception code: 0xc06d007f

After disabling network access, a fresh Codex process was observed for about four minutes with zero new matching events.

This does not prove that the network sandbox directly causes the native exception, but the network-access toggle is a reliable trigger/workaround for the UI regression.

Expected behavior

Enabling network access for workspace-write should not cause progressive UI lag, long Settings loading, slow thread switching, or repeated process-level exceptions.

Request

Please investigate the Windows network-sandbox initialization/reconciliation path, including retries or policy refreshes that may block the desktop UI or trigger repeated native failures.

Related but not duplicate

• #19238: workspace-mode/ACL behavior, but no network-toggle A/B comparison.
• #25207 and #18675: network connectivity failures, while this report is a desktop performance regression triggered by enabling network access.