There’s currently a bug in the game, that you cannot use the in-game browser to connect to the server, if it has a password. Our server has a password of course, the usual.
The only way to reliably connect is to do it through STEAM itself. If you have a friend currently playing, you can go to View -> Servers -> Friends tab, and connect to it from there. You should also Favorite it so that you can connect when none of your friends are on.
The game loads oddly when you connect in this way. It will start up and sit at the main menu as if you didn’t connect at all for about 10 seconds… then it will freeze for a few seconds while it actually makes the connection. Just don’t choose any menu options while its waiting there.