If you can't find the server then please make sure that the server name is set correctly in the cfg\server_cfg.ini file.
If it is set correctly try to restart the server. If that doesn't work you could try running the steam update function.
Important: There is a problem with the steam update tool from Kunos Simulazioni. Apparently they think it's a good idea to overwrite the server_cfg.ini file when we run an update. This results in the default server name being set to AC_Server.
We've implemented a system that renames the files and restores them after the update, but it's still a good idea to make a backup.