Today (after a very long waiting period) the domain has finally been transferred to my new hoster. As you are able to see the login for the admin panel, the correct IP is already reachable from your device. I added the SSL certificates a few hours ago and the site should already be available for most devices.

I still get the SSL warning when I visit SteemWorld from my location, but that's because my local DNS didn't refresh (update to the new IP) yet. When I change my local DNS settings manually (by editing /etc/hosts) it's working.

If it should still not work on your device, just give it a bit more time or (if you can) edit/refresh your local DNS cache ;)