Sorry, this relates to the Escapists 2, the store page linked me to these forums.

The tag Offline User is displayed at bottom of screen and if i try to start a game it says "You are disconnected from online services". FIrewall is open, so any instructions?

Did you ever figure this out? I'm having the exact same issue. Says "offline user" on the bottom, and no option to play multiplayer.

Thanks.

I've sent a support request. And got the answer, that it works via GOG Galaxy Client.

I have verified it, Multiplayer Online Works, when you install GOG Galaxy Client and start with it!
Works also cross Plattform (Steam/GOG etc.)

It's also currently noted on the page of the main game: Notes: Online Multiplayer requires Galaxy authentication.

Cheers