[Bug] Window previews are broken/missing when Stage Manager is enabled

[dashnomadpaid]

Describe the bug

When macOS native "Stage Manager" is enabled, the window preview thumbnails in the AltTab switcher do not display correctly. Instead of showing a proper preview of the window's content, they appear as empty, broken, or misaligned graphical artifacts. I expected the previews to render clearly as they do when Stage Manager is turned off.

Screenshots / video

https://drive.google.com/file/d/1PR2D_tzX3Rm4t_jGO3qCU2NujTkcL2Li/view?usp=sharing

Steps to reproduce the bug

1. Go to macOS 'System Settings' > 'Desktop & Dock'.
2. Click on the toggle to turn on 'Stage Manager'.
3. Open several app windows to populate the Stage Manager groups.
4. Trigger AltTab (e.g., Option + Tab) and see that the window thumbnails in the list are not rendered correctly.

Your environment

• AltTab version: 10.9.0
• macOS version: Tahoe 26.3.1 (a)(25D771280a)
• Other relevant info: Stage Manager enabled. Using MacBook Air m1 (2020)

[darr1s]

Same here, it might be related to "Display have separate space" in mac settings.