When you rest the mouse on the top of the screen in the full-screen view in Internet Explorer 11, auto-hidden tabs and address bar are not displayed as expected unless you exit full-screen view.
To resolve this problem, install the most recent cumulative security update for Internet Explorer. To do this, go to Microsoft Update. Additionally, see the technical information about the most recent cumulative security update for Internet Explorer.
Note This update was first included in March cumulative security update for Internet Explorer (MS15-018).
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
See the terminology that Microsoft uses to describe software updates.