Fortunately, there are several troubleshooting steps and solutions that users can try to resolve the Alt Tab issue:

Windows 11 includes dedicated settings that alter how application windows and browser tabs are displayed. Misconfigurations here can make the shortcut appear completely broken. Fix the Window Display Rules

Windows 11 relies heavily on the Windows Display Driver Model (WDDM). The Alt + Tab interface (the task switcher overlay) is rendered by the Desktop Window Manager (DWM). If the Graphics Processing Unit (GPU) driver is corrupt, outdated, or currently engaged in an exclusive full-screen mode that improperly releases focus, the DWM may fail to render the switcher interface.

A bug where Game Mode or a stuck Explorer process breaks Alt+Tab. The Desktop Window Manager restart fixes it 90% of the time.