[BUG] Windows: Claude desktop window stays on top of Alt+Tab, and computer-use screenshot returns blank gray image

Summary

On Windows 11, two related problems with the Claude desktop app (Code tab):

1. While the Claude window is open (not minimized), Alt+Tab appears to switch, but the screen keeps showing the Claude window. Other apps never come to the front. If I fully minimize Claude, Alt+Tab between all other apps works normally.
2. Computer use screenshot returns a completely blank dark-gray image (about #1f1f1f), even for apps that were granted and visible (File Explorer, Google Chrome). Desktop, taskbar and wallpaper are not shown.

This looks similar to the existing reports of the window staying on top / focus-locked on Windows (claudeissues mirror of "Windows: app window is always-on-top with no way to disable it", and "Claude Desktop window gets stuck anchored/focused when Computer Use starts"), but happens here without a running computer-use task.

Environment

• Claude desktop app (MSIX/Store package) version 2.37337.1.0
• Windows 11 Home, build 10.0.26200
• GPUs: Intel Iris Xe (driver 30.0.101.1298) and NVIDIA GeForce RTX 3060 Laptop (driver 31.0.15.5195), hybrid graphics
• One physical display, 2560x1440 native, Windows scaling enabled; the screenshot tool reports a 1456x819 frame and Windows reports screen bounds of 1463x823
• An extra virtual adapter named "Sharing Monitor" is present
• Several Electron/Claude processes running; cua-driver.exe is also running

Steps to reproduce

1. Open the Claude desktop app and keep it open (not minimized), with other apps also open.
2. Press Alt+Tab to switch to another app. The visible screen stays on Claude.
3. Minimize Claude: Alt+Tab among the other apps works again.
4. Separately, in a Code tab session grant File Explorer and Google Chrome via request_access, then call screenshot (also after open_application for File Explorer). The result is a solid dark-gray frame; the tool text lists non-granted apps as hidden but nothing from granted apps is drawn.

Expected

• Alt+Tab, Win+Tab and the taskbar can bring other windows in front of Claude.
• screenshot shows granted apps and the desktop.

Actual

• Claude stays visually on top of everything while open.
• Screenshots are a blank gray frame.

Notes / not yet tried

Not yet tested: disabling HDR, setting Claude to the Intel iGPU in Windows graphics settings, scaling at 100%, clearing Cache / Code Cache / GPUCache under %APPDATA%\Claude, or disabling the virtual "Sharing Monitor" adapter. I can run any of these and report back.