Dear all, our apologies, although we had brought up the site last weekend and updated the DNS resolution. What we had overlooked is that we had a very old DNS service still running (dnsever.com) and forgot to update that DNS resolution service. Hence some people were able to login while others not, even worse sometimes it worked, other times it did not.
We have now deleted this "old" DNS service and all should be well.
If you cant access the site via the domain name then feel free to access it via the IP address for the time being until the DNS service has propagated the latest changes.
https://198.211.105.133