Not updating "Recently installed" apps
Start11 doesn't show certain apps in the recently installed apps section (for example installed through the Microsoft Store).
Taskbar doesn't autohide after clicking system tray
If you have S11 autohide enabled, the taskbar doesn't hide if you click the system tray unless you click somewhere else.
Switching between workspaces/desktops causes lags
If you switch between Windows desktops/workspaces (not monitors) you'll encounter general lags (noticeable by moving around the mouse)