I was hoping this team was good enough and experienced enough to avoid a stretch like this, but even the best teams can struggle with adversity.
I think in the early parts of the season, and with Milan healthy, they were good enough to overcome some of their flaws (not as sharp on defense, not taking great care of the ball, not working through the offense). Then you lose your premiere shooting threat, teams can pack the paint a bit, you suddenly become guardable and the flaws actually make a difference (and the big target is still on your back).
With all that said, the main factor IMO is the loss of confidence and swagger. Just need to string a couple games together, get Milan back, get some momentum and positive vibes, and I think they can return to being every bit the top 5 team that I think they are. The next 4 games are a great opportunity to make that turnaround.