Unable to connect to world

I have purchased playstation plus and I have done every update. My boyfriend has a playstation 4, both my brothers have a playstation 4 as well. When we all try to play online I am unable to connect to their worlds and they are unable to join mine. But all three are able to connect and join each others. Essentially I have to play split screen on my boyfriends playstation to join them. How do I fix this?