Well apparently the forums run through cloudflare proxy and that is probably why you can use them fine.
But yeah idk why you can't access our server directly, and I don't think there is anything I can do about it sadly.
I'd suggest you maybe just try to join over more unconventional way, maybe contact currently running FC about your problem and he can just keep track of you.
I don't know how command core would handle something like this case now a days :(.
It might also happen that you country is simply having the servers our websites are on, on some banlist, which would not be too surprising. You can probably find that out if you do a traceroute of the website access, if you know how to do that. Through it won't help you in anyway, to know.