I'd call Jeep customer care and explain the situation to them and ask for a free service contract. They'll see that one of their dealers dropped the ball and should do something to make it right.
The first '14 GC I bought wore through the trans cooler line at 369 miles, before I even got home on delivery day. Line was touching the front driveline from the factory. It did basically what you describe; random gear changes, slipping and lack of forward power. It eventually locked itself in park on the side of the highway after it pumped all its oil on the ground. After it was all repaired, it made a little groan noise on certain downshifts. Keep your ears out and listen and feel for anything unusual, no matter how slight from now on.
Long story short, I came to a trade in agreement with Jeep and ordered a new replacement GC for very little out of pocket. Before I went that route, they seemed very eager to give me a free service contract.
2015 WK2 EcoDiesel Overland 4x4 Billet Silver, ORAII, ATG
1990 Mercedes-Benz 300D 2.5 Turbo - 155k
No sparks allowed!