I do not know what browser you use, but most browsers have a debugger. For instance Firefox, the browser I use has something called developer tools. If you use/instantiate that and send a log to the devs, they would have something to go on and would be able to help you in somewhat better way. Realistically speaking through, there are usually 2-3 hops or maybe even more from your browser to a site in question in back. If any of those break you could have a situation.
One thing I usually do if I do get in such a situation is I use torbrowser and try different tor circuits to figure out if the issue is at the site end or at my end or somewhere in the middle. So there are plenty of ways trying to figure out stuff before jumping the gun.