So, the problem is when we want to join to our friend's session, he is in game with "friends only" setting, the game writes him as "Building a base" or "Exploring", but we are unable to join. If he sending an invite to us we cant accept, it writes: "Invite sender is not in a game anymore".
But he can join to all of ours sessions. We have tried everything with him, port forwarding, firewall exception (both on pc and router), NAT is on moderate setting, Checked out the "send gameplay data". Also he has a TalkTalk Router. Please help.