Use the Purity III template and have the problem, which in small screens (smartphone / tablet) appear after a short time of the submenus these disappear again and thus can not be clicked.
I have done something wrong with the settings.
On the home PC, so at normal screen size, everything works in the "hoover".
Here is the link to the page: http://www.thc-westerkappeln.de
I have the configuration exactly as specified. Also the 3rd Party extensions deactivated, unfortunately, nothing has changed.
Looking forward to your reply.
Do you still need information from me?