for some reason when party_minplayers is set to 1 the game stops searching for opponents and lobbies and doesn't make you the host. If you force the lobby to start the game, You are host, can mod the lobby but no one will join. There is also another method to force host, have people to join but mods will not apply. As if someone takes the host from you or, like in left for dead, you connect to some server to play your match.