It's either a poor Internet connection on your part, or your Internet Service Provider messing with your connection. The log files show that you remain connected from the server's point of view, so the disconnection is coming from your Internet/Internet Service Provider.
13.May.2017 15:23:49 server - 0 ::ffff:XX Incoming Connection 40 handled by thread 0.
13.May.2017 15:23:50 login - 0 ::ffff:XX User "XX" (22918) logged in.
...
13.May.2017 15:25:44 server - - - Client 40 disconnected: Socket closed.
13.May.2017 15:25:44 login - - - Character Nightstar (21434) logged out.
I recommend downloading the
standalone client, and playing with that - it encrypts your connection, which makes it harder for rogue Internet Service Providers to mess with or filter your traffic. If you can access some maps, but not others, it is very likely that your Internet Service Provider is messing with your connection, so using the standalone client that encrypts it is the way to go.
As a matter of fact, I can log in and access the map you're on perfectly, and multiple players have been able to access the map from the intro area just fine.