Menu Widget doesn't work in Packaged Project/ Standalone Game.

Hi. I have a little problem with my pause menu widget. Right now if you press “1” the game is paused and a menu should be shown.
The menu however only appears and works in the Editor Preview of the game and it only works when I don’t click somewhere in the application so that the cursor disappears:


In the packaged and standalone versions I have to press “shift+F1” to see the menu and interact with it and even then it acts strange because some menu points only appear when I hover the mouse over it.:


So it is definitely depending on wether the mouse is shown with shift+f1 or not.
It feels like I am missing some preferences for the widget…

Would be happy for any suggestions!