Tabs on single product page not working on mobile

Hi, I really like this theme. It seems very lightwight and stylish. But I have one issue in mobile view of single-product page. The tabs like “Bschreibung”, “Echt jetzt?” and “Ressourcen” are not working –?the content is not displayed in mobile view. Do anyone knows how to solve this? Best and thank you

The page I need help with: [log in to see the link]