Can't enter any char on Onyxia

Hello! I have an issue with entering at any character in Onyxia. I can login, can play on another servers, but when I try to enter any of my chars on Onyxia I see an error "Server is unavailable" after loading screen like when server is down. But my friend is online and server is alive and I still can't enter any char on Ony.

And as far as I can see it is not a ban or sonething. Because in my account on site I see "Account status: In good standing" and I can't create a ticket on ban appeal because can't choose any bans there.

An error is "Server is down".