Vienna Ensemble Pro Remote Control Issue on Windows (Step Input)

VSL has the possibility to control the Midi driver by a web-service (localhost or any network). For this you can use any web browser on the same or a different computer (or iPad…). This Web Interface connects to the Midi Driver + remote control of the Vienna Ensemble Pro Server. The browser shows the different playing samples in a matrix on screen, which is very convenient, especially when working during Step-Input. Selecting an item in the Web-browser puts the chosen sample trigger (control or key) in the Cubase midi track. All this works fine and comparable with inputting via a midi keyboard. However…

There is a annoying difference between working on a Mac compared to working on Windows. On a Mac all is working fine. On Windows Cubase is losing focus from the Step Input window as soon as I trigger something in the web interface. To be more precise: The web-interface is taking over control. As a result I cannot move the Timeline Position in Cubase (f.e. with my arrow-keys) to another desired position. To get focus back I have to click with my mouse in the Cubase window…

I guess this is not what one would expect?

Again, when working on a Mac all this does not happen and is it possible to use another device with the web interface.

Am I missing something? Or is this a bug?