in WordPress (under settings-permalink) I saved the premalink settings again but without any effect on the problem.
I checked the URLs of the links in the inner page menue (appaerance-customize-menus-inner page menue): It starts with http://…. When I copy the link into firefox they jump to the right section. But when I use the links of inner page menue firefox doesn’t show http://….. and the link doesn’t work correctly as described above.
Hope this helps?
thanks for you help. This changes the spacing. This was the “subtle” part of the problem.
The “real” problem occures in Firefox (Edge and Internetexplorer work fine). For the first links (Über uns / Leistungen) it’s ok but if you want to jump back from an inner menue to e.g. “Produktionen” or “Kunden” you are always landing on “Aktuell”.