Menue borders disappear while hovering – Enfold theme

Hi there,

Great theme!!!
First time I bought it the last week, and there will follow more, definetely :-)

Here my question:

After clicking the second menu-point “Über Uns” the site is scrolling to the “Über-Uns”-Section.
The menu is shrinking and borders appear between the menu-points.
So far so good…
but when I hover to another menu-point the border beside disappears.
This should not happen.
How can I change that?

please help me
Thanks in advance
Bernhard