Widget not able to take input upon launching game

Widgets are not getting proper input when a game is first launched. Until the player clicks in the window at least once, widgets will not respond to any hover events and the first click will not have any action. This also occurs if the player returns the game's focus by clicking on it's icon in the Windows task bar.

Regression?: No
This issue also occurred in 4.14

1. Download the attached project
2. Use the "Launch" command to launch the game for Windows or package the project for Windows and open the .exe
3. Without clicking on the window, hover over the button on the screen and then click on it
   Result: The button's hover event (turning yellow) is not triggered and the first click input is not taken
   Expected: Since the game has focus, the hover event happens without needing any extra input and the first click even works on the button