I have ps4, and sometimes (almost every other night) my friends aren't able to join each other's parties, yet still talk in private chat.

Is this a cod issue or psn? Apparently Xbox users have been having the same type of issues but haven't heard anything on a fix.

If one friend can join one night, the other cant. Then it changes the next night where the friend that couldn't join can but the one(s) that could can't now

Some weird shit. My internet is fine - moderate nat type.

One friend has an open and the other 2 friends have moderate also.

Any suggestions ?