Party members being left behind

My friend group has had this problem every few matches as well and it's usually a different person each time who randomly gets left behind. Tonight all four of us were on Xbox and using the custom search thing to find a squad deathmatch match. We literally could not get all 4 of us into a squad deathmatch match no matter what we tried. Always one or two of us were getting left behind at the menu. We tried rebooting, restarting the game, changing party leaders and nothing worked. We tried a ton of times with no success. If we tried joining with just 3 people in the squad, we were able to get 3 of us in a match most of the time. Honestly, it's pretty ridiculous for this kind of bug to exist almost 2 months after the game released especially since I think it was also a problem during the beta.