Nope, nothing is wrong.
Provisional Division assignments, like the ones you received, are derived from qualifying population. At some point you were Gold among those who'd qualified. Now, as more people have qualified you've moved back.
Among your 1550 or whatever yesterday, you probably laid a few eggs, those games counted, too.
Additionally, your daily rating doesn't take into account the quality of opponents (the formula is on bungie.net there's no value for 'Am I playing Steel or Onyx dudes'). So even in Steel - guys are going to have big games and put up 1700s - and that's good.
A high Day Rating is like being a great minor league pitcher, your Mom is proud, but you aren't on SportsCenter.