The servers are ok. We get reports of this kind of trouble from Russia quite frequently. The devs have investigated it thoroughly, and there is nothing wrong on Plarium's side.

It seems that the only "fix" is to try to find a network that works. Maybe VPN, if you have access to it. So far, no one who tried it reported back, so I don't know if that actually works, but it should.

You're right..

What's a little confusing about this issue is that it logs into the account without any problems. 

Thank you for your attention to the matter!