This is a bit strange for my single server ISPconfig setup (Ubuntu 16.10 and apache)... Everything working OK until I created a client for a friend (he was the first client I created as admin). I gave the server IP and he did something on his side with his domain registrar worldnic.com Then this morning I started to see strange behaviors with my sites such as angelright.com and angelrights.com - if I access them from HTTPS then I have no problem seeing what should be seen. However, if I access them from HTTP then both redirect to my friend's website fishcafe.org I did create my own private DNS ns1.angelright.com and ns2.angelright.com (pointing to the same server IP) and I could let him use these and hopefully that could solve the problem. But this still leaves a hole for others to hijack all my sites as one can easily find the site IP. I tried turning on Rewrite HTTP to HTTPS for domain resirect, but this does not help. So why this? How could I solve this problem?