Good day.

I can't figure it out, when I enter a new site, there is a redirect to the old one, what is the reason?

There was a domain name "site.org", they forgot to renew it and it was taken away, I bought a new domain name "site.net".

We are using ISPManager 6. We added a record about the new site. An empty folder corresponding to the site name was created, into which we then copied the site files from the "site.org" folder. Using a test search, we replaced "site.org" with "site.net" everywhere.

In DNS, we deleted everything that was associated with "site.org" and added a new record "site.net", IP data, A, AAAA records, everything is the same as it was indicated in "site.org".

When entering "site.net" there is an immediate redirect to "site.org", error Status Code: 301 Moved Permanently

I have already reviewed everything I knew on the hosting, in DNS, on the forums, cleared the browser cache, nothing helps.

Tell me which way to look or what I did wrong.

Here's the thing: a 301 redirect is a permanent redirect, which means it's cached by browsers and can be a real pain to debug. Given that you've cleared your browser cache and still experience the issue, it's likely that the problem lies elsewhere.

One possible explanation is that there's a lingering redirect rule somewhere in your setup.

 This could be due to a few reasons:

Legacy redirect rules: It's possible that there are still redirect rules in place from the old domain that haven't been updated or removed. Check your ISPManager 6 settings, as well as your .htaccess file (if you're using Apache) or web.config file (if you're using IIS), for any redirect rules that might be pointing to the old domain.
CNAME records: Although you've updated the A and AAAA records, it's possible that there's a CNAME record still pointing to the old domain. Double-check your DNS settings to ensure that there are no CNAME records referencing "site.org".
Server-side redirects: It's possible that there's a server-side redirect configured on your hosting platform or in your application code. Check your server logs to see if there are any redirect requests being issued by the server.
Plugin or module interference: If you're using any plugins or modules on your site, they might be interfering with the redirect. Try disabling them temporarily to see if the issue persists.

To further troubleshoot the issue, I recommend the following:

Use a tool like curl or wget to test the redirect from the command line. This will help you determine if the redirect is happening at the server level or if it's a browser-specific issue.
Check your server logs to see if there are any redirect requests being issued by the server.
Verify that your DNS records are propagating correctly using a tool like dig or nslookup.

Swap out the index.php for a non-WP file (like a simple text file) and launch it in an incognito browser. If no redirect happens, then the culprit is likely a WP core file or function, possibly a sneaky .htaccess directive or a plugin gone rogue. Time to debug and isolate the issue, maybe even bust out some WP-cli commands for a deeper dive.

Draw your attention to the configuration file residing at the apex of our website's directory hierarchy. Within this pivotal file, you'll discover the essential credentials for establishing a seamless connection to our database, including the hostname, username, and password.