Im aware many of you who have downloaded gz off of gamepas have been struggling to access multiplayer but ive done something that hopefully works for u too.
Step1: In the main menu, click on multiplayer and search for a multiplayer game until u access one
Step2: Leave that lobby and open your saved game
Step3: press the pause menu and click multiplayer, hopefully the offline message wont appear and you’ll be able to invite your friends.
This has worked for me so hopefully this works for you. If this fails to do so im afraid i don’t have any other methods yet.