I am new to the site and have been browsing around! It looks like on some Overlands there is something in the center of the bottom black grill. I dont have that on my JGC Limited. I dont even see it on all Overlands.
That is a common problem and Jeep knows about it and as a result they are going to release a software update in the near future to rectify it. The exact date is not known yet but check back soon for an answer.