be at cross purposes
To be in conflict with or in opposition to someone or something. You will never find success if you continue to be at cross purposes with your teammates.
be/talk at cross ˈpurposes
(of two people or groups) misunderstand what the other is referring to or trying to do: Mary and I spoke about Anne for a minute or two before I realized we were talking at cross purposes: I meant Anne Smith and Mary meant Anne Harris.