Can't get more than 2 logged into a 10 slot server

  • I am very new to setting up servers, but I believe I covered the basics. Setup server, set map to A1 1x1 grid, started server. I was able to find it and log on, but I have 3 others I would like to be able to join. My daughter on a laptop joins fine, and I join fine. My son joined once, and hasn't been able to join since. He can find the server, but it always times out. All computers are in the same house. We haven't had trouble joining servers together before. Maybe I am missing a setting? I know that isn't much to go on, but any help would be appreciated.