[BUG] Claude Code hangs - cannot interact. CPU Utilization at 100+%. Must force quit process to terminate. #3214

Environment

• Platform (select one):
  • Anthropic API
  • AWS Bedrock
  • Google Vertex AI
  • Other:
• Claude CLI version:
• Operating System:
• Terminal:

Bug Description

We're trying to roll out our pilot, and we have users that experience intermittent locked sessions -

They are unable to type, interact at all with the Claude Code session. The process has to be terminated with a kill -9. CPU Utilization is at 100% for the hung process.

Steps to Reproduce

1. Launch Claude Code with claude
2. hangs - no interactivity whatsoever.

Expected Behavior

We should be able to interact and utilize Claude Code.

Actual Behavior

Have to force kill the process.

Additional Context

Here's our env setup

export CLAUDE_CODE_USE_BEDROCK=1
export AWS_REGION=us-west-2
export CLAUDE_CODE_MAX_OUTPUT_TOKENS=4096
export MAX_THINKING_TOKENS=1024
export ANTHROPIC_MODEL='us.anthropic.claude-sonnet-4-20250514-v1:0'
export ANTHROPIC_SMALL_FAST_MODEL='us.anthropic.claude-3-5-haiku-20241022-v1:0'