Codex in-app browser X composer repeatedly fails with clipboard/editor state

I am using the Codex desktop app with the in-app browser to help manage a real social-posting workflow on x.com. The workflow is: Codex finds a post, drafts a reply, stages it in the X composer, and the human user reviews/edits/approves before posting.

This is extremely useful when it works, but the browser/editor interaction is failing often enough that the workflow becomes brittle.

Environment

• Codex desktop app on macOS
• In-app browser logged into x.com
• Target editor: X reply composer / contenteditable text field
• Human remains in the loop for final approval

What happens

After one or two successful staged replies, Codex often fails when trying to fill the X composer. The visible/runtime error presented to the agent is:

Browser Use encountered an error interacting with this webpage's clipboard: Browser Use virtual clipboard is not installed

Other related behavior I saw in the same session:

• Filling the composer sometimes appends the new draft to the old draft instead of replacing it.
• Select-all/delete did not reliably clear the composer contents.
• Opening a fresh X tab sometimes fixes it, but not always.
• Fully reconnecting/resetting the browser session and opening a fresh tab usually fixes it.
• The problem appears more likely after the human user manually interacts with the browser/editor between Codex actions.

Repro shape

1. Open Codex desktop app.
2. Use the in-app browser logged into x.com.
3. Navigate to an X post.
4. Have Codex stage text into the reply composer.
5. User edits or manually posts, then asks Codex to stage another reply.
6. Repeat across a few posts.

Expected: Codex can reliably replace the text in the active composer.

Actual: the composer may fail with the virtual clipboard error, or duplicate/append stale rich-text contents instead of cleanly replacing the draft.

Why this matters

This is not just a toy browser task. The workflow was: AI-assisted social/content operations with human approval. Codex was genuinely useful at finding targets, drafting replies, and keeping the user honest, but the browser bridge/editor state issue kept breaking the flow.

A reliable first-class way to set text in modern contenteditable editors, or a more robust fallback when the virtual clipboard is unavailable, would make this kind of human-in-the-loop browser workflow much more dependable.