Windows: browser connection repeatedly disappears; REPL reset cannot recover and native Computer Use fallback is unavailable

Environment

• Windows desktop app; installed package OpenAI.Codex version 26.908.4834.0 (read from Get-AppxPackage).
• Computer Use skill bundle: 26.908.40834.
• Chrome browser extension integration.
• Observed repeatedly September 8–12, 2026, in the same ongoing task.

Problem

Browser control intermittently becomes unavailable, blocking an ordinary web form / replacement-order workflow. The agent cannot recover using the exposed reset and browser-creation APIs.

On September 10, cua.getState() returned a Chrome extension browser with tabs. Browser control then successfully completed a multi-step form and verified its submission confirmation.

On September 12, the browser inventory was empty again:

{"apps":[],"browsers":[]}

Creating a new tab through cua.createBrowserTab("chrome", ...) returned:

Browser is not available: chrome

Resetting the mcp__cua_repl JavaScript session, reinitializing it, and retrying discovery / tab creation did not restore access. These were session resets, not verified restarts of Chrome or the underlying native service. The exact trigger for losing the browser connection is unknown.

Native fallback / tool availability

The Computer Use skill instructs the agent to use node_repl with @oai/sky, but no separate native node_repl tool was exposed in the active tool inventory. The agent tried importing @oai/sky in mcp__cua_repl; the import succeeded, but sky.list_apps() failed:

Trusted RPC service is not configured: sky

This fallback was attempted in the browser REPL, so the error alone does not establish a native backend crash. It may relate to the tool-routing / surface-availability problems described in #44986 and #42745. It is also not established that the empty browser inventory and native RPC error share a cause.

Expected behavior

When an authorized browser workflow loses its connection, provide actionable connection state and a supported reconnect path. If native Computer Use is available, expose the correct documented tool; otherwise clearly distinguish unavailable capability from a service that can be restarted.

Impact

Repeated recovery attempts across multiple turns failed and the user's workflow remains blocked. Please advise which diagnostics are needed to distinguish extension disconnection, tool routing, and runtime service configuration.

No conversation transcript, account identifiers, customer correspondence, addresses, images, or raw logs are attached.

No source files or tests are identified in the report. Start by reproducing the empty result from cua.getState() and the failure from cua.createBrowserTab("chrome", ...), then compare browser-extension, tool-routing, and native-service diagnostics. Done means the connection state identifies the failure class and a supported reconnect path or capability limitation is clearly exposed.