Error when I try to invite a friend to play coop on UT

I get an error every time I try to invite a friend on Ultimate Team to play coop Rivals or any other mode apart from Rush, saying game session is already full or is no longer available. It worked fine until two days ago and my friend can invite me and i can join his lobby, but i get the error as soon as i press triangle to invite. We’re both on PS5. What is the fix?