Last Header Menue item is sticky

[hello-kathi]

URL: https://dev.liqd.net/de/projects/
user: all
expected behaviour: I click one menue item and the drop down in coming, if I click another one the "old" menu item is gone and teh other opens.
behaviour: The "Mitmachen" drop down is always there
important screensize:
device & browser:
Comment/Question:

Screenshot?