Advanced Steam Session Plugin , invited friend loads on wrong level

[YdleHU1]

Hello!
I am developing a Coop mode for my game, and I am using the Advanced Steam Session plugin available in Unreal Plugins. I made a Lobby map
where I can use buttons on platforms with unique tags to invite steames friends to my lobby.
The integration of the plugin into my project is definitely good, because the Steam Overlay is displayed and my friends are listed, plus
it also recognizes my avatar and my steam name. I’ve built my game and use steam_appid 480 to open spacewar
to test it. The problem every time is that my friend gets the invite ,but when he accepts the invite he never drops it on the lobby map
my friend, but to the mainmenu start level, every time.
Default level is set to “MainMenu” level, where when I click on “Coop” button ,the following happens:

In Maps & Modes in Project Settings, I have the Game Instance shown in the picture set, and I create the Create Session there:

When I use the Open Level By Object Reference node in “listen”, what happens every time is that it loads the “Multiplayer_Lobby” level, and then it loads and returns to the menu, but the log says Session on that level and in MainMenu is In Progress.
I don’t know why this is happening, I tried loading the Multiplayer_Lobby level with the ServerTravel node instead of the Open Level and it seems fine, it loads successfully
into the Lobby, but when I invite my friend and he accept it, it throws him into the menu afterwards.

Also, I tried that when I click on the Coop button in the menu, it loads a new empty level first, where I set the regular GameMode and create the session on that level. The result is that it loads the empty map very quickly, then loads the Multiplayer_Lobby map, where it also throws me back to the MainMenu in a flash.
I also tried to make the starting level the Multiplayer_Lobby in Project Settings, but then the invite doesn’t arrive, and it wouldn’t work for me anyway, because I want the default level to be the MainMenu.
If anybody has any clues or ideas, I would really appreciate it, because I have been struggling with this problem for weeks.
Thanks in advance!

[YdleHU1]

To clarify things, this instant back to main menu thing is while trying to create a session only happens when I use the “listen” tag in Open Level blueprint node.

Edit: I found some other cases here on the forum that Open level with “listen” doesn’t work for others. I’m using version 5.2 and what I found about “online subsystem” I copied everything into the DefaultEngine.ini file. Could this be some kind of bug? Or do I need to make some other settings to get it to work properly?

[YdleHU1]

I managed to solve my problem. The problem was with the “online subsystem” plugin, it wasn’t enough to enable the plugin and put the necessary configuration in the DefaultEngine.ini, I had to modify the “target.cs” and “Build.cs” files in the C# code and add 1-2 lines of modification, rebuild the Build.cs after the modification. There is yt tutorial about it, who has such problem, what are these modifications. Finally, if the plugin is already activated, you need to unactivate it and reactivate it after the changes and it will work