Tracking teams/player score throughout rounds

In a simple 1v1/2v2 map, i want to know which team won the previous round.
Trying to track the team’s score through out the rounds of a game, seems to be a difficult task.

I added a ScoreManager to the scene, and attached it to my script (through @editable)

 OnBegin<override>()<suspends> : void =
        ScoreManager.ScoreOutputEvent.Subscribe(OnScoreChange)

OnScoreChange(Agent: agent): void =
        Print("Score Changed!")

When a round is completed, i see the score of the teams change, but the callback is never called.
I have also tried

Score := ScoreManager.GetCurrentScore(Agent)

Where Agent is a player who won a round, the return value is always zero.