[BUG] Windows Desktop: Previous prompt block persists as floating overlay on subsequent responses

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?

On the Windows Claude Desktop app, a previous prompt's code block sometimes persists as a floating overlay on top of subsequent responses. The ghost element stays rendered on screen even as new assistant messages appear below it, partially obscuring the actual content.

The overlay appears to be a stale rendering artifact from a code block in an earlier message. It floats on top of the response area and does not scroll away or disappear. Scrolling, clicking, or waiting does not dismiss it.

This makes it difficult to read subsequent responses since the floating code block covers portions of the text.

Steps to reproduce:

1. Start a conversation in Claude Desktop (Windows)
2. Send a prompt that generates a response containing code blocks
3. Continue the conversation with follow-up prompts
4. Observe that the code block from the earlier response remains rendered as a floating overlay on top of newer responses

Screenshot attached below.

What Should Happen?

All prompts from previous responses should not persist as floating overlays. Each response should render independently without visual artifacts from earlier messages.

Error Messages/Logs

N/A — no error messages. This is a visual rendering bug only.

Steps to Reproduce

1. Open Claude Desktop on Windows
2. Start a conversation
3. Continue sending follow-up prompts
4. At some point, a prior response will remain rendered as a floating overlay on top of newer responses
5. The overlay does not scroll away or disappear — it stays fixed on screen

Note: This is intermittent and may take several exchanges before it occurs. It seems more likely when responses contain large code blocks.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Desktop (Windows) — latest as of 2026-05-12

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

This bug occurs in the Claude Desktop GUI app (Electron), not the Claude Code CLI. The Terminal/Shell field is not applicable — selected "Other" as
there is no "N/A" or "Desktop app" option.

<img width="769" height="896" alt="Image" src="https://github.com/user-attachments/assets/cedddf49-4d1a-4276-a03c-9605f7c79433" />

Screenshot showing the floating code block overlay: