Codex in-app browser cannot complete D&D Beyond Google sign-in

Summary

The Codex in-app browser cannot complete Google OAuth login on D&D Beyond. Clicking "Sign in with Google" does nothing from the user's perspective, and browser automation cannot interact with the Google sign-in control because it is inside a cross-origin iframe.

Steps to reproduce

1. Open the Codex desktop app.
2. In the in-app browser, navigate to https://www.dndbeyond.com/my-campaigns.
3. Click Sign in.
4. Click Sign in with Google.

Expected behavior

The Google OAuth sign-in flow should open and allow the user to authenticate, so the agent can continue with the user's authorized task.

Actual behavior

The Google sign-in button does not work in the in-app browser. In this session, automation reported:

Unable to translate Input.dispatchMouseEvent in the in-app browser: Input targets inside cross-origin or inaccessible iframes are not currently supported in the in-app browser

The fallback to a Wizards username/password login is not viable for users whose D&D Beyond account must use Google sign-in.

Impact

This blocks agent workflows that require logging into sites where Google OAuth is the only usable login method. In this case, the agent could not access D&D Beyond campaign pages to update a Notion character database with D&D character levels.

Environment

• Platform: macOS
• App: Codex desktop app
• Browser surface: Codex in-app browser
• Website: D&D Beyond
• Affected URL: https://www.dndbeyond.com/sign-in?returnUrl=https://www.dndbeyond.com/my-campaigns

Additional context

The actual browser/Chrome backend was not available in this session, so there was no working fallback to a browser where the user was already signed in.