AskUserQuestion tool auto-completes with empty answers without showing UI

Bug Description

The AskUserQuestion tool returns immediately with empty answers without displaying the question UI to the user. The tool appears to auto-complete without any user interaction.

Environment

• OS: WSL2 (Ubuntu on Windows)
• Claude Code Version: Latest (as of Nov 2025)
• Terminal: Windows Terminal / WSL bash

Symptoms

1. Claude calls AskUserQuestion with properly formatted questions
2. Response returns immediately: "User has answered your questions: ."
3. The answers field is empty (note the period after colon with no content)
4. User never sees the question chips/options on screen

Expected Behavior

The question UI should appear with selectable options, wait for user input, then return the selected answers.

Actual Behavior

The tool returns instantly with an empty response as if the user had already answered (but with no answers).

Reproduction Steps

1. Start a Claude Code session
2. Have Claude use the AskUserQuestion tool with any question
3. Observe: No question UI appears, empty response returned immediately

Investigation Notes

I investigated whether custom hooks in ~/.claude/settings.json could be causing this issue:

• Hooks use PreToolUse with matcher: "*" to intercept all tools
• AskUserQuestion has no registered handler, so it passes through with permissionDecision: "allow"
• Hooks only do allow/deny decisions before execution - they cannot modify response content or suppress UI

Conclusion: Hooks are not the cause. This appears to be a Claude Code internal bug.

Possible Causes

• Plan mode may interfere with AskUserQuestion UI rendering
• Race condition where response returns before UI displays
• WSL/terminal rendering issue with the chip UI component

Additional Context

This issue has persisted for several months across multiple Claude Code versions. It occurs both in and out of Plan mode.

Settings Configuration

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "*",
        "hooks": [{"type": "command", "command": "/root/.claude/hooks/user-prompt-submit.sh"}]
      }
    ]
  }
}

Even with hooks configured, AskUserQuestion should work since it passes through with "allow" decision.