[BUG] User messages disappear from chat history after assistant response is rendered

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?

In the Claude Code desktop app (Code mode), user messages intermittently disappear from the chat history after the assistant's response is fully rendered. Two consecutive assistant responses appear directly stacked as if no user message was sent in between.

The message IS visible while the assistant is processing (during the "Frolicking..." loading state), but vanishes once the response completes. The assistant clearly received and acted on the message — only the UI rendering is affected.

This appears to happen more frequently in long conversations where context window compression may have occurred, and particularly with short user messages.

What Should Happen?

User messages should always remain visible in the chat history as separate bubbles between assistant responses, regardless of conversation length or context compression status.

Error Messages/Logs

No error messages. This is a silent UI rendering issue — no console errors observed.

Steps to Reproduce

1. Open Claude Code desktop app in Code mode
2. Start a long conversation with many back-and-forth exchanges (20+ turns with tool calls, code edits, etc.)
3. Continue until the conversation is long enough that context compression likely occurs
4. Send a short message (e.g. "sildim kontrol et" — a brief 2-3 word instruction)
5. Wait for the assistant to process and fully render its response
6. Scroll up to review the conversation history

Observed: The user message from step 4 is missing from the rendered chat. The assistant's response to it appears directly below the previous assistant response with no user message in between.

Note: The message IS visible during the loading/processing state (see screenshot 1) but disappears after the response renders (see screenshot 2).

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude 1.1.9310 (cb30ac) 2026-03-27T17:11:42.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

<img width="893" height="600" alt="Image" src="https://github.com/user-attachments/assets/cb2cd159-817b-41ab-b5c9-7fc3c6bb2b51" />
<img width="892" height="600" alt="Image" src="https://github.com/user-attachments/assets/d83125b7-9e6d-41e0-b201-73f3affd103f" />