Agent gets stuck in 'working' state with 0 tokens after completing turn

Description

After an agent finishes its turn, Claude Code sometimes enters a stuck state where:

• The red "working" indicator appears
• Token count shows 0 tokens
• A timer runs indefinitely (observed for 1+ hour)
• The agent does not respond to new input

The only way to recover seems to be force-quitting or interrupting the session.

Environment

• Claude Code version: 2.1.17
• OS: macOS 15.6.1

Expected behavior

Agent should return to idle state after completing its turn and be ready to accept new input.

Actual behavior

Agent gets stuck showing a working state with 0 tokens and a running timer, sometimes for over an hour.