Level closes immediately after opening when using advanced steam sessions

I created a multiplayer frisbee game with advanced steam sessions. When I create a new session and open a new level, the new level runs for less than a second and then returns to the default level. This problem wouldn’t appear if I don’t use steam. Please help!

Hello! Did you manage to solve it?
I am in the same situation, the game starts in my “Lvl menu”, I enter the “Lvl city” and from the Lvl city I do Host; The Lvl city opens but the second the Lvl Menu opens…

Try running this in standalone and then post what your server log says. It will give you a good indicator of what it is thinking and doing when loading new levels when all this happens. Seems to be a lot of unknown stuff going on here. Does PIE give you any warnings after exiting the game?