Long response after multiple parallel tool calls not rendering in UI

Description

When Claude Code executes multiple parallel tool calls (e.g., 3 concurrent Bash searches), and then provides a detailed text response summarizing the results, the text response does not render in the UI. Only the collapsed tool call summary is shown (e.g., "Searched knowledge base for Michel Gros and Burgundy wine information").

Steps to Reproduce

1. Ask Claude Code a question that triggers multiple parallel Bash tool calls (in this case, 3 concurrent qmd query searches)
2. Claude returns results from all 3 tool calls
3. Claude then calls 3 more tools in parallel to retrieve full documents
4. Claude writes a detailed multi-paragraph summary response

Expected Behavior

The full text response should render below the collapsed tool call summaries.

Actual Behavior

The text response after the tool calls is not displayed. The user only sees the collapsed tool summary line. The previous shorter response (from an earlier turn with fewer tool calls) rendered correctly.

Environment

• Claude Code (VS Code extension / desktop app)
• Model: claude-opus-4-6
• macOS Darwin 24.6.0

Screenshot

The user confirmed via screenshot that the detailed response text was completely missing from the UI, with only the collapsed tool call summary visible.