When loading a map, how can I join to dedicated server?

Well, I have a dedicated server working well (MyAppServer.exe). I just start it and I can play my App by just double clicking in the package I generated (I mean, by double clicking MyApp.Exe). In fact, I can continue playing in several laptops and I can see other players.

My problem is, If I am in a level A (the level I can see with player one, player two, and so on) and go to level B and again return to level A. My player is out of the scene and lose the connection to the original level.

Do you know what am I doing wrong?

I have to mention that the level A when is opened, it doesn’t do nothing to connect to the server. I do that in a level called Transition Map that connects to my IP. But I don’t know the right blueprint to connect again to a level.