What's wrong with the Heat?

I don't know about you people but if I see a without a doubt potential championship contending team play as bad as the Heat are playing, I would be astonished. I don't care if it's a team I dislike, I would want them to lose but not the way the Heat are losing, it just doesn't make sense. Like, I'm okay with them losing to the celtics, but they almost got blown out. What's wrong with them? Is it the coach, the gameplan, it can't be the Big 3? LeBron was probably frustrated because I saw him miss a bunch of Free throws. I think it's probably the 1 and 5 positions. Also what about the Magic, they are getting their a*ses handed to them?