Windows: deterministic 21–42 second latency in shared Computer Use/CDP bridge

Codex App version: 26.901.4073.0
Computer Use runtime: 26.901.31953
Edge: 152.0.4191.53
ChatGPT Edge extension: 1.26.901.11451
Platform: Microsoft Windows 10.0.19045 x64
Session ID: 01a06cfd-46c6-79d3-8bea-1eeb444b079c

Issue

Browser discovery and lightweight tab metadata return immediately, but DOM, accessibility-tree, and raw CDP requests consistently incur large, step-like delays—even on https://example.com.

Observed timings:

• Browser discovery: about 0.5 seconds
• Tab title read: 1–3 milliseconds
• DOM snapshot: about 21.1 seconds
• Accessibility state: about 24.5–42.2 seconds
• Raw CDP Page.getFrameTree: about 42.4 seconds
• Initial in-app browser creation/state: about 63.4 seconds

Reproduction

1. Start Codex Desktop on Windows.
2. Open https://example.com using Edge Computer Use or the built-in browser.
3. Read lightweight tab metadata; it returns immediately.
4. Request a DOM snapshot, accessibility state, or raw CDP frame tree.
5. Observe consistent delays in approximately 21-second increments.

Isolation performed

• Fully restarted Codex: no change.
• Fully restarted Edge: no change.
• Closed every Edge and extension-host process.
• Repeated the test using only Codex’s built-in browser: the same delays remained.
• Network and WebSocket checks pass.
• CPU and memory were not saturated.
• Installed Computer Use runtime files match the files bundled with the Codex package.
• The runtime is app-managed and is not independently uninstallable.
• No repair or unsupported runtime modification was performed.

Expected behavior

DOM, accessibility-tree, and basic CDP calls on a trivial browser session should return within a few seconds, without deterministic timeout-scale pauses.

Assessment

The fixed timing pattern and cross-browser reproduction suggest a retry/timeout loop in the shared Windows Computer Use/CDP relay rather than an Edge-extension, network, or model-reasoning issue.

Possibly related: #40048, but this report adds quantified raw CDP/DOM/AX timings and reproduces after Edge and its extension host are completely absent.

Start by reproducing the reported Windows session against https://example.com, comparing browser discovery and tab metadata with DOM, accessibility, and raw CDP requests. Use the quantified timings and isolation results to investigate the shared Computer Use/CDP relay; done means identifying and resolving the deterministic 21-second retry or timeout pauses and confirming normal response times.