Menu layout changes when selecting category from menu
I updated my site and installed a new template (Purity 3 from Joomlart). Most things seem te work fine. One of the things that's not working as expected is the menu. Once I select a menu item containing a category the layout changes to another color and on a mobile device it does not look as expected.
I have added 2 images. One containing the expeted behaviour (black drop down) and one that shows the menu after selecting the category menu item (white dropdown).
Did I forget something on configuring the menu items? Link to my site is: https://gpscyclingtracks.net
For the mobile layout I made some small changes in custom.css so the look and feel is a little bit acceptable.
Oh, and all plugins etc. are up to date.