[BUG] Claude Code not working anymore with Cloudflare Warp active

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?

I can't work anymore with Claude code and with Cloudflare Warp active Version: 2025.8.779.0 (20251006.32)

I keep getting message "Unable to connect to API due to poor internet connection", and nothing happens.

• Tried with All MCP server disconnected.
• I have 300 Mbps Download and Upload, with Wired OR wireless Networking. So this can't be a poor Network issue.
• If I turn Cloudflare Warp OFF -> Claude Code works.
• ZERO Changes in Cloudflare Warp Configuration ( 100% sure )
• No recent macOS update

Claude Desktop is Not affected.

It NEVER happened before and I've always used Claude Code with CF Warp turned ON since I use Claude Code.

Same issues with any cli: VS Code, macOS Terminal, Ghosty or Warp.app

What Should Happen?

Never had issue before. my last session is 2 weeks old.
Always have worked with Cloudflare Warp and Claude Code since day 1 of using Calude Code.

Error Messages/Logs

⎿  Unable to connect to API due to poor internet connection
     Retrying in 7 seconds… (attempt 5/10)

Steps to Reproduce

1. have Cloudflare Warp turned ON.
2. run Claude
3. ask anything in Claude Code.
4. wait for message:``` ⎿ Unable to connect to API due to poor internet connection

Retrying in 16 seconds… (attempt 6/10)

### Claude Model

Sonnet (default)

### Is this a regression?

Yes, this worked in a previous version

### Last Working Version

not sure

### Claude Code Version

v2.0.24

### Platform

Anthropic API

### Operating System

macOS

### Terminal/Shell

VS Code integrated terminal

### Additional Information

can't tell latest Claude Code working version. Last session was ± 2 weeks ago, early October 2025