Windows: QWidget's windows don't receive touch events after new QWidget have showed

Compile and run project in attachment to reproduce bug.

Touch PushButton and hold it at least one second. Release button.
You should see that new widget window have opened.
After that you can't to move both windows and close them with window's red close buttons with touch. Apparently, widgets have stopped receiving touch events.
You can restore proper window behavior if you focus non-application's window (like windows explorer) and then return focus to one of application's window.