My server address is redirect to a random website ??

Hi .. my server (example.mydomain.org.au) is redirecting to a completely random, never-before-visited website (https://cassianowines.com.au/) which has an odd not authorised certificate from geo someone.

This only happens when I try to access the server address via safari from another computer on the network.

How can I stop it redirecting? What am I doing wrong?

Thanks in advance.