Menu is not working on mobile devices

I made a website for the first time. I used WordPress because it is an easy to use application to develop websites. I have only one problem. The drop-down menu is not working on mobile devices. As soon as I touch a submenu it goes back to the main menu. In other words I cannot reach the page I want to look in. Is there a solution to this problem? Thanks in advance for your reaction.

URL: http://www.beheerrijstrookstellendamstraat.nl