Republishing an artifact closes its popped-out window and loses typed text (Windows desktop app 2.9939.2)

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?

Since the Claude desktop app updated on Sept 24, 2026, when Claude Code republishes an artifact that I have popped out into its own window, the popped-out window closes and the artifact reappears in the main app window. Anything I was typing in that window is lost, including an unsent comment and text in form fields on the page.

Before that update, republishing updated the popped-out page in place, and I could keep commenting while Claude revised the artifact.

Actual: the popped-out window closes, the artifact reopens in the main window's panel, and the typed text is gone.

What Should Happen?

The popped-out window stays open and updates to the new version, keeping my unsent text where possible.

Error Messages/Logs

No error dialog or crash log; the window simply closes silently.

Steps to Reproduce

Step 1: In a Claude Code session in the desktop app, have Claude publish an artifact with the Artifact tool.
Step 2: Pop the artifact panel out into its own window.
Step 3: Start typing a comment, or type into a text box on the page.
Step 4: Have Claude republish the same artifact from the same file (new version, same URL).

Reproduced in a brand-new session with a brand-new artifact. Claude made no request to show the panel; it only republished. Popping out the whole session, or opening the artifact in a browser tab, doesn't work for how I review.

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Claude desktop app 2.7032.0

Claude Code Version

2.1.281 (Claude desktop app 2.9939.2)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

OS: Windows 11 Pro (build 26200). Terminal/Shell field above doesn't have an option for the desktop app itself; this bug is in the Claude desktop app (Code tab), not a terminal.