Recreational Vehicle Lpg Tank Valve/gauge problems of the 2018 Chevrolet Silverado 1500

Been having voltage issues for a couple of days where my lights dim and volt gauge drops and raises while driving or stationary dealer said it's normal also hard down shifting while driving not letting off the gas assistant brakes have failed and clunk hard sometimes when stopping or press hard back at me through the pedal again dealer said it's normal I pulled my truck out from the back of the house to the front shut it off to go get ready for work a couple minutes later my daughter informed me my truck was over heating I went to door to find smoke pouring out of my truck from under the hood grab a fire extinguisher run out pop the hood and the whole passenger side of compartment is in flames how does a vehicle that's not running start on fire? awaiting my insurance company to get it out of here I imagine will be a total loss there isn't much left of the engine bay so not sure what started the fire.

I bought this 2018 silverado brand new 20 miles on it I had problems since the first day I drove out of the dealership truck has loud noise inside the cabin coming fryghe doors 6 months after the gauges are not reading accurately took back to the dealership and they kept for a month they fix the gauges bug the noise still happening worst truck ever for 40 k I own a 2004 and the inside is really quiet also the paint is chipping the dealership says it's cause the driving conditions I would understand if it was in the front of the truck but paint is chipping in the side and back of the truck I did my research and look on youtube and there's a lot of people complaining about this Chevrolet should really look into this before we all go and trade it in for a Ford I have pictures of this I'll try to post it if I can look at the gauges even when the truck is off.