Multiplayer Player Lobby

Hello Everyone, Can someone guide me how to create a Multiplayer Lobby? Where I can invite friends and all.

P.S: I am very fluent in cpp and have created almost everything even created a session that works as session and can send invites but on invite accept, I get EOS LobbyPresenceExist Error. I understand you have to leave a session to join another. But this is not very optimal, like we see in Fortnite or PUBG.

Any help will be appreciated.