Site resolves to www in Firefox and without in Chrome

Everytime I’ve seen the thing you’re describing it was due to the browser having the redirect cached.

I can’t see any reason that different browsers would behave differently in this case. You may want to try a browser/machine you haven’t used before to access this site as this will show you definitely what’s happening.

You could also reply here with the domain and with a tool like wget/curl it’s easy to see exactly what redirects are happening.