Never had this issue: when i alt tab to something, it doesn't toggle. Or clicking on icon on taskbar doesn't bring that up. While start menu experience host is running. Also when i bring up pop out window from chrome and want alt tab back to main window - main window isn't showing, but maybe is more of a chrome issue, i don't know. Sometimes i also alt tab and mouse cursor disappear, it is like i would be alt tabbed to that window, but i still see old window from which i alt tabbed.