Scroll position snaps to top of conversation when scrolling during response streaming

When Claude is actively streaming a response, scrolling up (even slightly) causes the viewport to snap all the way to the top of the conversation history — showing the oldest messages — rather than staying near the current scroll position or the active response.

Expected behavior

Scrolling up during streaming should either hold the current scroll position or, at most, snap back to the bottom where the response is being streamed.

Actual behavior

The viewport jumps to the very top of the conversation (earliest prompt/response), requiring manual scrolling all the way back down.

Steps to reproduce

1. Have a conversation with several prior exchanges (enough to scroll)
2. Send a prompt that produces a long response
3. While the response is streaming, scroll up slightly
4. Viewport snaps to the top of the conversation

Environment

• Claude Code v2.1.81
• macOS (Darwin 25.3.0)
• VS Code 1.112.0 integrated terminal