hyphenation doesnt work for some words

Hey! I tried everything I could but the word “sicherungsdienstleistungen” in the first red box (title shows only “sicherungsdienst”) does not get seperated correctly. Interestingly in the box on the right side nearby it works without any problem. How do i resolve this?

Thank you in Advance.
Sebastian

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