[BUG] First 20s of loading Claude within WSL - 1s on 1s off (terminal alternates between showing changes and not showing changes)

Environment

• Platform (select one):
• [ ] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [X] Other: Claude Code
• Claude CLI version: 1.0.93 (Claude Code)
• Operating System: Windows 10
• Terminal: VS Code Terminal -> WSL

Bug Description

I open a terminal in vs code in Windows. I run WSL. I run claude. For the first ~20 seconds the terminal alternates every ~1 second. For 1 second it shows changes to the terminal (including characters I type) and then for 1 second it does not. After the 1 second of not showing changes, it then suddenly shows all the changes. So it is receiving input as I type, just not displaying the characters.

Steps to Reproduce

1. Open Terminal in VS Code on Windows 10
2. type wsl and hit enter
3. type claude and hit enter
4. First ~20s it has this issue

Expected Behavior

Terminal should show all changes and input immediately

Actual Behavior

Terminal alternates every second between showing changes (including my input characters) and not showing changes

Additional Context

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