I think the original drop of points was due to a number of factors, biggest being complacency and thinking we can walk the ball into the net every game. The in-game complacency and lack of intensity invited opponents to get the better of us solely due to them wanting it more, despite the sheer lack of quality between most of our opponents and us.
A few other factors would be making substitutions too late, while the opponent benefits from their earlier substitutions and Enzo doesn't react quick enough. Then during the time we were dropping points, there wasn't much fight from any of our players. The team frequently plays with too much arrogance and thats costed us multiple times.
So its a mix of tension and energy levels, but the latter isn't seeming to be an issue because we keep possession every game and are never the ones chasing the ball. So it gives us the upper hand, as far as energy levels and stamina is concerned.