This is a known issue from 2011 thru 2015 since they are all designed the same in that area. The painted door edge goes to the edge of the exterior plastic cladding, so the door edge is not protected from being exposed to the bottom of the rocker panels, which are in the path of constant road debris.
If not actually rubbing something, the constant flow of grit, sand, road rocks, etc from travel goes into the rocker channel & wears away the door edge paint, and since the doors drain thru the seals and breathers by draining down the door, alot of moisture can be all along that rocker lip regardless.
In the thread about this, there are pictures, as well as the only thing to do to minimize damage. Clean the door edge and rocker drip edge constantly, and apply paint protection to the bottom of the doors.
There are also members who made a foam seal by applying foam weather seal strips to the door edge, and painting them to match.