ONLINE CROSSPLAY PS5/XBOX SERIES S

Having problem inviting my friend to a game of ultimate team, we play some nights and it works fine other nights we go online and it says no friends online when I go to inv him to a game through the friends but we can join each others ea party, we are both on the correct version of fc sometimes it works sometimes it doesn’t. No consistency got a ps5 thinking wouldn’t have problems playing together but the cross play is a real let down