S510, no interactive click possible

After updating to windows 10 the Dell S510 Interactive projector doesn't register clicking through the pen anymore. Before everything used to be fine.

I tried updating to the latest firmware and drivers, but this made no difference.

When you click the screen, you can see a circle showing around the place that is clicked but nothing happens. Also you can drag a window around but when you let it go, it just shifts back to the Original position.