Unable to play Mut h2h or Champs

Since yesterday I keep getting a server error message when loading up a h2h or a champs game. Ive deleted and reinstalled and still can’t play . Anyone else having this issue or know how to fix?

I had an issue as well.  I created a new lineup and ensured that none of the players in my Specialists are unique players (i.e., all players are in my Defense or Offense lineup).  That fixed the problem.  I don't know why this is an issue right now, but it apparently is.

I'm on XBox Series X/S, by the way.