So I like to play with my brother and his girlfriend plays with us as well, I play from my house (ps4 pro) and they play from two separate ps4's at their house (one pro and one reg). If I and one of them plays together, no issue. If they play together, no issue. If all three of us try to play together we get constant disconnects, or are able to play for a little bit before being disconnected. After an initial disconnect sometimes the person disconnected won't be able to join the party, gets constantly errored out with "Unable to Join" messages, or the fireteam is full because a ghost version of the kicked player is still shown in the fireteam temporarily. If the kicked person is able to join back in often another player is disconnected from the fireteam in the process. This has also happened with another player present in the fireteam, we were trying to do trials with another person, and the last part of our trio was able to join, but was always immediately removed from fireteam. This has been probably the most disappointing part of Destiny 2 for me and them, because we enjoy playing together.