[BUG] User messages disappear from conversation history in UI

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?

User messages (prompts) are not displayed in the conversation view. Only Claude's responses are visible, leaving no record of what was typed. The messages are being received and processed correctly — only the display is broken.

To reproduce

Open Claude Code (desktop or web UI)
Type a message and press Send
Observe that the message does not appear in the conversation — only Claude's response is shown

Environment

Affects both desktop app and web UI simultaneously
Started suddenly, not caused by a settings change

Additional context

Because the issue occurs on both desktop and web at the same time, this appears to be a server-side or account-level issue rather than a local client problem.

I've done a full reboot on my machine, as well as cleared all the caches in my desktop and web UI. I can verify that this is happening across all archived work sessions, and it appears to be constrained to Claude code and nowhere else that I can find.

What Should Happen?

Expected behavior

Both user messages and Claude responses should appear in the conversation history.

Error Messages/Logs

none

Steps to Reproduce

To reproduce

Open Claude Code (desktop or web UI)
Type a message and press Send
Observe that the message does not appear in the conversation — only Claude's response is shown

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.0.2339 (1782e2) 2025-12-16T19:35:52.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Confirmed it is also exhibiting the same behavior using OPUS 4/6.