Mouse functionality breaks on Linux when game is full screen on multi-monitor setup

When the game window is maximized on any monitor other than the left most monitor, the mouse will not interact with the game window.

Two monitors required for reproduction

1. Open UE4 Editor (blank project)
2. Add UMG widget blueprint (MyWidget)
3. Add button to widget
4. Set button "Appearance->Style->Hovered->Tent" color to red
5. In level blueprint, add the following nodes
   • BeginPlay, GetPlayerController, Set ShowMouseCursor (from GetPlayerController), Create Widget (Class is MyWidget), Add to Viewport (From CreateWidget return value pin)
6. Wire nodes in the following order:
   • BeginPlay->Set ShowMouseCursor->CreateWidget->AddToViewport
7. Play in standalone mode
8. Press Alt+Enter to switch the window to full screen on primary monitor
9. Click in game window to give focus
10. move mouse over button - button changes from white to red
11. Press Alt+Enter to exit full screen
12. Move standalone window to secondary monitor
13. Press Alt+Enter to enable full screen on secondary monitor
14. Move mouse over button

Result:
The button does not highlight when the game window is full screened on the non-primary monitor

Repro Rate:
3/3