Since a few weeks, I have a strange behavior between Fences and some maximized windows applications.
Fences seems to be in the foreground on the top of the app window (see picture link here under).
I see the Fences's mouse cursor over the top some maximized applications ( Acrobat Reader DC, Remote App, Microsoft Outlook (sometimes), Edge, Chrome, ...), and the application's toolbar / menu / windows controls are hiden with a blank zone.
the window title and the minimized, restore and close buttons are displayed but not clickable.
Using alt-space, I can display the window system menu and use the restore menu to un-maximized the application window, and then the application's menu / toolbar / windows controls buttons are back clickable.
In the picture here, you can see a snapshot of a maximized Acrobat Reader DC with the blank zone and the Fences's mouse cursor.
System : W10 Enterprise 64-bits V 1809 build 17763.107, Intel i7-8700, 16GB Ram