New Installation and Problems

I did a fresh install on a new server and there is no way to get NextCloud to work, on the old server I just installed it and it worked now on the new server I did a lot of things and can't get it to work.

There is also a WordPress website that I copy them as is and it doesn't work... another WordPress website did not present me with any problem placing the same configurations that they had before

Just a couple of points for you to verify. after you add a domain or subdomain, you have to make sure of a few things.

First, give it time for the new domain to propagate, a quick test is to us nslookup <domain.tld> from a Linux command line, if it returns the IP of your server, you are ready to go.

Second, once the domain is pointing to your server, enable SSL on the site. From user cpanel.domain.tld > Domains > AutoSSL, select the domain from the dropdown and click Install.

Third, in cpanel.domain.tld, go to CWP Settings > Php Selector  and choose from the dropdown menu your domain, then select your PHP version and click Update Version.

Yes, the new server is the replacement of the previous one, we have only changed the domain name of the server... it is only in the test one.

the dns have been delegated for weeks

I did a fresh install on a new server and there is no way to get NextCloud to work...

I personally don't feel that NextCloud is compatible with a standard LAMP/LEMP server profile. I personally have a dedicated VM just for a NC instance, with configured ZFS storage backing. It's just too different of an animal to shoehorn it into a standard shared hosting profile.