Weekends seem worse than weekdays. I have the save game, GF has to receive invite, or find my lobby in Multiplayer. Usually it takes many tries before she can finally see the lobby I create, and recreate, etc. Last night, I started by creating a lobby with her login, which I can immediately see, no problem, consistently. However it took 2 or 3 tries before she could see my lobby so she could log in and load save.
Saturday night took nearly an hour to get her logged in to our game, and that seemed by random chance.
The problem persists that if she accepts an invite when she can't see my lobby, then she loads into someone else's game.
Now I just keep creating new lobbies until she can see me, then all works perfectly. Note: she has to exit Multiplayer also if she can't see the lobby. If you're already looking at the lobbies in Multiplayer, and a new lobby gets created, your screen will not refresh from our experience. You must go out to the Main Menu, then go into Multiplayer again.