Disconnect all clients when Steam connect

Hello!

There was a question on the use of “servertravel” and the plugin “AdvancedSession”.
If I run 2 clients on the LAN, then everything works fine (Use or Not AdvancedSession).
If I run 2 clients on the Steam (I’m use AdvancedSession), I’m not find a game.
If I run 2 clients on the Steam (I’m not use AdvancedSession), I’m find games, but I’m not correctly connect to this game: My client found game → I’m click “connect” → All clients exit in MainMenu. What wrong?

Screen in Lobby:
Game Mode:

PlayerController:

Widget:

Screen in MainMenu:

Screen in MainMenu: