Steps to reproduce:
1. Download and open attached project "SecondDisplayCursor.zip"
2. Build standalone (including "Test" scene)
3. Play it in full-screen mode (secondary monitor)
4. Move mouse over the cube

Actual result: If the build is played on the primary monitor, everything works fine - moving mouse over the cube changes cursor.
If the build is played on the secondary monitor, nothing happens

Expected result: Consistent behavior in all monitors (mouse cursor changes when moved over cube)

Notes: Does not seem to be impacted by any other settings. Changing from full-screen to windowed mode with Alt+Enter, and then dragging it to other screen, making it full-screen again, change the behavior depending if its primary screen or not

Tested and reproduced on:
Windows 10
Unity 5.1.4f1, 5.2.4p1, 5.3.4p3, 5.4.0b15