Definately not normal this early, I assume it is the passenger rear coil? I have heard of spring sag occuring after a period of time, but never that quick. Normally you can get spring Set which happens when you compress the coil completely so the individual coils are touching, but that won't happen on a stock Rubi. Now I do have about a 1/4" difference side to side. I would have a dealer look at it just in case.
Stupid me, as a matter of fact I do have a massive rear tire relocator with a large steel bumper. I am sure I have added 100 pounds to the back. Thanks for clearing my mind. I knew it would be worth while talking to people with other Rubicons. I will take it in though for inspection. It sure is great to have a warranty!