Okay, interesting. So it does work with a different DNS provider. Can you visit the IP address of the site without any issues (with/without Google DNS?)
You can retrieve the IP address of this forum by visiting:
And typing in simpcity . su
I will not post the IP address of the forum in here for privacy and security reasons, please make sure you don't do so either, unless an Admin on this forum asks for it.
Can you try to copy the IP address that whatismyipaddress puts out and put that in the address bar of your browser?
I would be curious to see what happens, maybe try to do it first without setting a different DNS provider.