Description:
MacBook Air M5, using only built-in display. The login window renders full screen normally. After logging into desktop session, the display canvas gets cropped with a black bar on the bottom-right corner.
This issue is reproducible in Safe Mode and with a brand-new admin user account. No third-party display or window management software installed.
Suspected WindowServer display coordinate calculation bug within user session.
Environment
Device: MacBook Air M5
OS: macOS 27.2 RC (26B118)
Display: Built-in display only, no external monitor
Reproduction steps
Boot to login window, display works fine
Log into desktop session
Display canvas cropped, black bar appears at bottom-right
macOS 27.2 RC (26B118) Built-in display canvas cropped with black bar at bottom-right after login
This issue first appeared starting with macOS 27.2 beta3. The bug still exists in 27.2 beta4 and 27.2 RC. I hope this can be fixed for the official release.