[BUG] computer-use MCP: batch actions disrupt window Z-order across all monitors on Windows multi-monitor setup

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?

Environment

• OS: Windows 11 Enterprise 10.0.26220
• 3 monitors: Notebook 2560×1440 @150%, LG 24" 1920×1080 @100%, TV 42" 1920×1080 @125%
• Claude Code on Monitor 1, target app (XXXX WinForms) on Monitor 2, unrelated apps on Monitor 3

Behavior

When a computer-use batch starts (the overlay appears on Monitor 2), Windows reorders Z-order on ALL monitors:

• Monitor 3 app (Firefox, not fullscreen) gets minimized
• Claude Code on Monitor 1 changes from maximized → restored
• When the batch finishes, a different window is brought to foreground on Monitor 3

Notes

• Occurs regardless of whether open_application is called
• Triggered at the exact moment the computer-use overlay appears — before any left_click or key action executes
• Keyboard input reaches the correct target (left_click before keystrokes ensures focus), so functionality is correct
• Side effect is purely window management disruption on unrelated monitors
• Consistent and 100% reproducible across multiple test runs

What Should Happen?

Run Computer use in app on monitor 2 without perturb any other app neither self Claude Code app in other monitors

Error Messages/Logs

Steps to Reproduce

Reproduction

1. Claude Code on Monitor 1, any app on Monitor 2, any app on Monitor 3
2. Trigger any computer-use batch targeting Monitor 2
3. Observe: Monitor 3 app minimizes at batch start; a different window maximizes on Monitor 3 at batch end

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.15962.1

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_