Database redirecting site

Hello!

My site is blank, and when asking the host they said that the database seems to be redirecting it to another URL. They can’t see where this is happening. It has worked fine for a long time, then the site was blank when you put www. in front of the URL, but it worked without www. Now it is always blank.

The site is a copy of another site, so that may be the problem. The database is trying to redirect to the site that it is a copy of. But why did this suddenly start after over a year of working fine, and how can I find out where in the database this happens?

Thanks!