I have trouble connecting with them (NC) from time to time.
I think it is often because they use CloudFlare to mitigate bots and DDOS attacks. I don't think it is always configured properly and/or may have an issue with your IP range.
Also try a different browser to see if that helps. I keep a couple of "portable" version of browsers on hand to try just in case I think I might be having a browser specific issues with a site.