My infallible expert and educated advice is to get rid of that GC to the first sucker you can con into buying it even if you have to pay him.
I have never heard of a vehicle having such outrageous dependability issues and nobody from factory to dealer to owners can isolate an underlying fault other than the vehicle is hopelessly unfixable or it's running now let's cross our fingers it stays that way for a week or two.
It's a vehicle. It should start and get you where you need to go then shut off. It doesn't need to be this difficult.
I'm driving its competitor, a Honda Passport/Isuzu Rodeo, which was bashed for lacking the Jeep's luxury amenities and car like refinements.
Ha. It never breaks either!
Not trying to rub it in because I do feel for you. This shouldn't be happening.