Chat stream display corruption: lost responses and stacked messages in long/multi-session usage

Bug Description

In long sessions and when switching between multiple Claude Code sessions, the chat stream display becomes corrupted. Responses are generated (confirmed by asking Claude to repeat them) but fail to render, and message ordering breaks down.

Symptoms

1. Claude responses vanish — Claude generates a response but it never appears in the chat stream. No error, no spinner — just silence. The response exists (see workaround #2 below) but was never rendered.

1. User messages stack at bottom — Instead of interleaving with Claude responses in normal conversational flow, user messages pile up together at the bottom of the visible chat stream.

1. Out-of-order rendering — When Claude responses do appear, they sometimes render above the stacked user messages rather than in their correct chronological position.

Reproduction

• Primary trigger: Switching between multiple concurrent Claude Code sessions
• Secondary trigger: Extended sessions (long back-and-forth conversations, especially after context compaction)
• The more you switch between sessions, the worse it gets

Workarounds

1. End and restart the session — partially resets the display state, but doesn't fully fix it
2. Ask Claude to repeat itself — "Tell me again in its entirety the last thing you told me" recovers the lost content, confirming the response was generated server-side but not rendered client-side

Analysis

The fact that workaround #2 works proves this is a client-side rendering/message-queue issue, not a generation or streaming failure. The response content exists in the conversation history — it just wasn't displayed. Likely a race condition or stale state in the chat stream renderer when switching session contexts.

Environment

• macOS (Sequoia)
• Claude Code CLI
• Multiple concurrent sessions via separate terminal tabs

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🤖 Generated with Claude Code