So tried it in private match with a friend, me as host, EAC and F13 blocked in my firewall rules, script working properly. After the game intro cutscene finishes it's stuck on a black screen and eventually my friend gets kicked for "error: could not authenticate connection".
Does the 2nd person also need EAC disabled?
If someone wants to try it again with me my dis cord number to add me is #6898.