Hey, when using a touch device, you can have multiple fingers “active” on the screen :P.
The code currently, for example the CursorPointerIndex and WidgetsUnderCursorLastEvent in SlateApplication treat some things with just one cursor in mind. This causes wrong events and no events to be fired sometimes when more than one touch is active.
Can you update to the 4.8 release and check if you’re still seeing the same issues? Please be sure to make a copy of your project when opening in the update.