Nav Bar goes Crazy dont know why?

[Leonard_Franke (Schnueffler)]

Hey Fellas,

i need your help !

visit following website :

GROTZKE - Sachverständigenorganisation Röntgentechnik

try the Navbar “Team” or “Kontakt”
They becam black then back normal and again black…

The Home and service button work fine…

Please help !

Greetings
Leo

[Leonard_Franke (Schnueffler)]

i found out that it changes at one specific point of the page to a current stage ?

Dont know what this is and how to fix it ? Please help me !