You wouldn't happen to have an aftermarket dual batt system would you? The reason I ask is that on the Genesis system the start stop system will error out after a number of ESS stops/restarts (can't remember the actual number, I think it's 6 or 7). I permanently disabled that system within 1 month of buying my JL, also the 2018's seem to have the most problems with that system, there is a software update that prevents a dead aux batt from not allowing your Jeep to start, have you had that done? I wouldn't bank on the fact that your batteries are new, that little barbie car batt they put in the aux slot is known garbage, and on a 2018 without the software update a dead aux battery will not allow the starter to engage (the starter relay circuit is only activated by the aux batt, unless as I said you have the software update or a jumper on the high amp buss bar).