Double domain url, where does it origin?

Design help CMS
#1

Very strange, we published our website with the domain: https://www.manadental.at last week.
Now we can find all of our URLs as a 404 error with the domain www.manadental.at/www-manadental.at It seems like there is a copy of our page, but i can not find it in webflow.

Where does the double domain URL origin and how can I delete it?

Looking forward to your help.

Thanks in advance.

Here is my public share link: [LINK]
(how to access public share link)