4k monitor support with touch and mouse does not work

Mouse and touch support seems to become unresponsive when the editor is running on a 4K panel. Certain play modes will allow click events to work while others do not when running on a 3840x2160 display.

Repro with attached project:

1. Open the attached project in UE4Edtior
2. Play in Standalone Game
3. Press K
4. Click the Sphere

Result:
The success line prints, mouse location is modified

Expected Result:
Success line prints, mouse location is not modified

Workflow Repro (not using attached project):

1. Create an actor Blueprint and add a mesh to it. (sphere used in example)
2. Create an on click event for the sphere and link it up to a print string
3. Create an on input touch begin event for the sphere as well and link that to a print string.
4. Set up a Blueprint player controller to use the mouse cursor when playing. ( example sets "K" as the key press to show mouse cursor)
5. Attempt to click on the sphere in a 1080p environment (This should work and the print screen will display)
6. Attempt to click on the sphere in a 4K environment (This will not work and no print screen appears)

In 4K different play modes seem to offer different results. For example just using PIE seems to work ok but using play in new window seems to be broken.

Widget Button Focus Resolution Problem