I really hope this bug gets fixed in the next release.
The main reason I use [x][Show Mouse Cursor] is because it enables you to seamlessly & efficiently work between the viewport and other windows without having to press SHIFT+F1 to show the mouse cursor whenever you need to navigate to another window.
Since 4.11 I have to constantly keep pressing SHIFT+F1 which is a real productivity killer, especially when you’re trying to debug blueprints/materials or any setting that requires moving the mouse out of the viewport.
I trust the dev team is still on it, and really hope it gets fixed as soon as possible.