Friend does not show up

My friend is on PS4 and I am on pc. Yesterday we were playing fine in his world and today I try to join his world and I keep getting the error; Unable to connect to world. Both of our NAT types are open, neither of us are using firewalls, and we both deleted each other and re-added as friends and nothing is working. He can't join my world and I cannot join his. In the xbox companion it doesn't even show him as playing any game. On the MC menu when searching for a game in friends, he doesn't even show up, although in the companion he shows up, just not playing anything. Also, I cannot add him to my realm.