Why do all sites on one vps show the content of one site?

Question

linux

There is a VPS for warming up mailings. It has PowerMTA installed. 5 sites are running on apache. Each has its own ip. But, for some time now, all sites have begun to show the content of the site, which is considered the main one. We didn't find any settings in apache. Tried moving sites to another directory, same thing. The hoster is spying on us. As a result, they paid him money for reinstalling the server. The problem is the same. The hoster is spying on us again. There is no redirect. The URL is different, but the content is the same. Already blowing the roof off.