Empty/missing sections one OnePager Startpage after using Website Navigation

Hi,

I have a massiv problem with a customer Website:

Home

The Startpage is a onepager Website but there are some extra sites, e.g.

Coole Jobs

The OnePager Start Page is working correctly when first loading the page, BUT after navigate to one of the underpages, e.g. https://brain-project.de/jobs/ and then use the menue again the startpage shows emtpy section allthough exactly this sections ARE THERE and have loaded when first starting the page.

Try this to reconstruate the problem:
1. Open https://brain-project.de/
2. Click in the Menu on “Coole Jobs”, getting to https://brain-project.de/jobs/
3. Click in the Menu on “Vorteile”
4. YOu’ll see the problem –> empty/White spaces

I Already tried everything, including deactivating all plugins, reinstall WordPress, the Unicorn theme etc.

PLEASE HELP (contact@pixxel-house.de)

Thank you

BR
Alina

Ticket