Stuttering / hitching in video playback when “Displays have separate Spaces” is disabled

[st-eez]

Body

Steps to reproduce

1. Open System Settings → Desktop & Dock → Mission Control
2. Disable “Displays have separate Spaces”
3. Open Safari or Safari web app for YouTube
4. Play any YouTube video on an external monitor
5. Tile the window in AeroSpace so it fills the entire screen (not macOS native fullscreen)

Expected behavior

Smooth, stable video playback without frame skips or rendering issues.

Actual behavior

Video playback exhibits rendering hitching — frames freeze briefly or update unevenly

Notes

• Reproduced in Safari and Brave.
• Issue disappears immediately after re-enabling “Displays have separate Spaces.”
• Occurs only when the AeroSpace-managed fullscreen (tiled to fill screen) is active.
• AeroSpace version: <0.19.2-Beta>
• macOS version: <26.0.1 Build:25A362>
• Hardware: <Apple M3 Pro>
• Reproducible every time.