[BUG] Rapid-fire duplicate printing during message cycle in first 5 minutes - v2.0.54 regression

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?

CRITICAL BUG - Version 2.0.54 - Rapid-fire duplicate printing triggered during typing, stops after Claude responds

ISSUE SUMMARY:
After upgrading to 2.0.54, experiencing severe message duplication with rapid-fire printing during the typing phase. Issue triggers within first 5 minutes of starting Claude Code.

EXACT BEHAVIOR PATTERN:

1. Start typing a message
2. Every keystroke triggers duplicate visual print (pyramid effect)
3. Hit Enter - message sends successfully
4. Claude begins responding with rapid-fire duplicate prints (10-20+ per second)
5. After Claude finishes response, rapid-fire stops and everything returns to normal
6. Issue may repeat on next message or resolve completely

CRITICAL TIMING:

• Only occurs within first 5 minutes of starting Claude Code
• Has happened twice, both times in this initial startup period
• After rapid-fire episode completes, Claude Code works normally
• Currently running 20+ minutes without further issues

USER INPUT PHASE (while typing):

• Every keystroke prints but doesn't send
• Creates pyramid effect:

t
te
tes
test

• Enter key works correctly - message sends

CLAUDE RESPONSE PHASE:

• Claude's response prints at extreme speed
• Estimated 10-20+ prints per second
• Same response printing repeatedly in rapid succession
• Makes output unreadable during this phase
• STOPS when Claude finishes responding
• After stop, everything works normally again

What Should Happen?

not rapid fire printing.

Error Messages/Logs

na

Steps to Reproduce

its happened 3 times the only constant was tming under 5 -1 10 minute

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.0.53

Claude Code Version

2.0.53

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_