How to enable touch input on Windows

I’m running with of_v0.10.1_vs2017_release under Windows 10 and need to get direct input from a touchscreen

In a simple test app I implemented

void touchDown(ofTouchEventArgs& touch);
void touchMoved(ofTouchEventArgs& touch);
void touchUp(ofTouchEventArgs& touch);
void touchDoubleTap(ofTouchEventArgs& touch);
void touchCancelled(ofTouchEventArgs& touch);

and called ofRegisterTouchEvents() from setup()

But the touch methods never get called.
When I touch the screen in the window mousePressed() gets called instead.

How can I enable the touch functionality?