My biggest surprise (and disappointment) is the Utah Jazz. They had an outstanding 2nd half of last season, a strong playoff run, an exciting young player (in D. Mitchell), a top-ranked defense and were bringing the entire team back.
Now, Mitchell seems to have not improved any, they have one of the worst defenses in the league and a losing record at home. I thought they'd be the 3rd or 2nd best team in the West and, right now, they are 14th in the West. The only team with a worse record is the Phoenix Suns.
While other teams (Rockets, Celtics, Spurs) are having bad starts - they all have changing and challenging circumstances that can explain their struggles. I have no earthly idea what is wrong with Utah or how they can fix whatever it is.