My son plays on the PS4 and I play on my PC, I can send him an invite from my PC and he can join me from the PS4 just fine. But it has only worked 1 time in reverse where he is able to invite me to join him in one of his worlds on the PS4. Now every time he tries to send an invite it shows all his cross platform friends as off line and we never get any sent invites. I can see him online and try to join through friends list but I get an unable to connect error. I have checked both Microsoft accounts to make sure we appear online, and made sure the worlds are set up for multiplayer. What am I missing?