Win 7 64Bit.
UE4 4.5 Preview
Widget Blueprint is added to viewport. It contains a button called Resume.
Widget Blueprint fires a blueprint interface event targeted at the HUD when you press the button.
HUD Blueprint removes widget from viewport.
On the controller BP.
Input Touch Event no longer detects it is pressed.
But it does detect it is released.
For testing i added a Get Input touch state.
When i touch this returns true.
This is why i believe it is bug. I might be wrong. But it seems like the answer.
Apologies if it is not.