Why does my session gets destroyed after "Join session"?

Hey first of all thanks for sharing your code very appreciated. I’ve tried the following:
In the gamemode (the gamemode is opened when opening the lobby-level):

In the gamestate:

Also a weird thing that the session still gets destroyed after hosting a game:

Why does the session gets destroyed (“No registered sessions”) but I am still able to find the session with my second window (the gameslot is NOT hardcoded it gets all sessions and lists them):

I can still click on it to join but the number of playercontrollers is still 1 after joining.

Maybe the session gets destroyed on one gameinstance and therefore i cannot join and the gamestate is not the same? (I also made a testcall but it only works locally and does not get replicated. Also the number of playercontrollers printed to the lobby window is 1 one both windows.)

Is it important that the player own a pawn? Everthing i’ve seen is always with a playercaracter (but i dont need one here because its only the lobby at that point).
Best regards and big thanks! M