Problem adding chain in the address

I have a problem.
On my Webmin + Virtualmin something happened and I can not figure out what.

This is reflected so that when you enter the main domain of our server
where website ran out of our range and contacts and so it happens that at the
end it added nalsedovné “new_domain.html”
Then it looks like new_domain.html”.
I tried to redirect the subdomain when directly entering reacts but after entering the root domain and redirecting them back again
So I entered the redirection even specific file index.html and it has been wholly wrong returned to

I can not seem to find where is defined something like this.
On the other domains do not do and works fine as well and only the subdomain of the main domain server do such things.