Start default site on internal domain

Hi everyone,

we have purchased a domain from Squqrespace and connected it internally to our web project.

As soon as I define a start page (Checkbox) in the internal project, I also have to define the slug. I have named this "/index".

When I now call up the domain, it does not load the web project. This is only possible if I add the slug /index, e.g:
younameit.com/index

Even if I leave the slug empty, i.e. leave "/" without a name, the domain in the root does not load the project, e.g. younameit.com. You must also add the "/" here, i.e. younameit.com/

It is particularly annoying,  that the start page in the menue of the web project, only ever refers to the domain younameit.com. But for the reasons mentioned above, the page does not load there.

Any tips or ideas?

Best
Erik