Advanced Session plugin : Can't find dedicated server session


I work on a dedicated server project in 4.27.0 on windows. I’m using the Advanced Session plugin with the steam subsystem.
A session is created in the gamemode of the server starting map and when the player clicks on a button in another menu map, the client is listing all the sessions online that it can find. But it won’t find my session.
For information, both server and client are packaged and launched on the same machine, the steam subsytem is working as the overlay works and the client finds 7 other sessions. I made the server display the session id and it doesn’t fit with all the ids i get on the client. I already read a lot of topics on this forum and others but i can’t manage to find a solution. I don’t have much experience in ue4 but i already used the plugin in this particular version and it worked, i don’t know what i did wrong.