[Excel Add-in] Keystrokes go to active cell instead of Claude input box; cell chip reappears after dismissal

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When using the Claude for Excel add-in, typing in the Reply/chat input box sends keystrokes directly to the active Excel cell instead of the Claude input field. The cell chip (e.g. "E124 selected") reappears automatically even after closing it with the X button, and any letter typed goes to that cell.

Additionally, a "Claude Fable 5 is currently unavailable" banner is shown in the panel, and the model displayed is Opus 4.8.

What Should Happen?

aText typed in the Claude chat/reply input box should be entered in that input field, not redirected to the active Excel cell. The cell chip should not reappear after being dismissed by the user.

Error Messages/Logs

Steps to Reproduce

a1. Open Excel with the Claude add-in panel open

1. Click on the Reply/chat input box (cursor blinks indicating focus)
2. 3. Start typing — letters are redirected to the active Excel cell instead of the Claude input box
3. 4. Try dismissing the cell chip (e.g. "E124 selected") by clicking the X — the chip reappears automatically

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

N/A - Using Claude for Excel add-in (not Claude Code CLI)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

• OS: Windows 11
• Model shown in the add-in panel: Opus 4.8
• Banner shown: "Claude Fable 5 is currently unavailable"
• This is a focus/keyboard capture issue specific to the Excel add-in (not Claude Code CLI)
• The cell chip (e.g. "E124 selected") reappears on its own after being dismissed with the X button