Rear suspension not level

[Xrs]

Hey guys ive just installed ACS suspension kit before thx giving then i drove it to chicago, and today i just notice that suddenly the right side of the rear is alot lower that the left one so i measure it, it is more than half an inch lower, i can fit 4 finger on the left side and 3 fingers on the left, Any idea, i brught it to the dealer but they can only check it on Thursday

Any insight would be greatly appriciated

[jst2878]

leveling sensor is out of whack

[Xrs]

Is this a big problem should i be driving the car around?
is it going to be expensive to fix it