Set Input Mode Game and UI errors

“Watch the picture again. I casted from Widget to UserWidget, not the other way around ;-)”.

Yes indeed that is exactly what you are doing wrong here. You create your Widget Active Instance which IS a child of UUserWidget, casting a child into parent is not meant to be in this case. Im also referring to this [Bugreport][1].
But it seems you can currently casting to a UserWidgetReference but FMPOV it shouldnt be able.

However having it like this:

should work out just fine. I test that and its fine.

BUT i am able to reproduce your issue and it seems to have some kind of relationship to this: [Bugreport][3]

Everything is locked to viewport, but when i am at the edge of the window inEditor or Standalone PlayMode and start clicking while trying to get off the viewport, i happen that the focus to the PIE is lost.

I think this can be considered as a BUG too.

best regards