I can't join my friends on PS4 even though they can join me

Me and my ps4 friend wanted to play Minecraft and I went in a world and he joined and I left and he made his own world and he did not appear in the joinable friends list so I asked if his setting was right and he said yes and he does have a Microsoft account and so do I and they need to fix this because all I want to do is play Minecraft with my ps4 friends