Display bug - navigation is hidden for no reason


I think I have discovered a display bug, or is it something wrong I did?

If you launch the Prototype:

you will see a navigation bar on top with text links. If you now click for example on the woman with the yellow shirt in the content area a new page will be launched where in the navigation area all text links are hidden. After a reload they appear. So it this a bug? Or is it my misconfiguration? The navigation area is a dynamic panel in a master with 3 viewports. the 2 versions of the dynamic panel you can see when you scroll down. but in both versions the text links are visible. I don’t have a rule to hide them.

Somebody an idea?
Thanks a lot,

Bug is gone! Don’t know why? Maybe a Browsercache-problem? But I always try multiple ones.

But okay, closed for me.