Prostar pos help

[Fubar]

No idea where to start but....... fixed the ac issue on my 2016 prostar Cummins isx... it was low on Freon 0.51 level. Paid $222 to get it vacuumed and recharged. Blows cold as hell now, coming back into Florida to be home for the weekend as I have a 2 drop outside from my house truck has been off for 5 hours and I was mowing my lawn n drinking. I go to my truck to get something and inside the cab I smell smoke. Looking around like a crazy person and I look out to the hood see smoke coming from the engine. I pop the hood see fire behind my fuel filter I grabbed my gallon of water and put it out without thinking. After freaking out I got down on the ground with a flashlight looking where it started. The starter was burnt also the harnesses around it so no idea how or why it caught on fire with my truck being off. Thankfully I have 15k miles left on warranty so I paid the $375 to get it towed to the dealer 47 miles away and now waiting to hear from them. Has anyone ever had that happen to their truck? I’m still at a dead end as to how it happened.