OceanWP mobile menu only works partially

Hello dear OceanWP community and OceanWP developers,

After reading through numerous forum posts here and also not finding a solution to my problem in the WP forum, I hope that you may be able to help me with my mysterious problem.
I have a page that works perfectly. It is designed as an onepager with OceanWP and Elementor, only imprint (Impressum) and data protection (Datenschutz) have their own subpages. So far it works well, BUT: when I open the page with my mobile phone and the mobile version is shown to me, something is wrong with the menu. I get all menu items displayed correctly, but when I go to “Projects” (“Projekte”) I don’t end up with projects, but at the top again. With the other menu items “Services” (“Leistungen”) and “Contact” (“Kontakt”) it works perfectly and there I did it exactly like that! I have no idea what I did wrong ?!
The menu navigation on the page works via anchors, which I have set and named exactly like the menu points. I have already tried to switch off the plugins one after the other and then switch them back on, but the error remains or I cannot find the bad plugin (if it was because of it). I have to say that I am not a professional and have taught myself how to build websites using WordPress. So I’m still a beginner.
Maybe someone has an idea here, what the origin of this bug is? You would help me a lot!

Thanks in advance,

atombaron

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