Recreational Vehicle Lpg Tank Valve/gauge problems of the 2016 Subaru Outback

I had a major issue with this vehicle on June 24. We were driving back from our family vacation when I was passing a semi truck on a two lane road the vehicle suddenly lost power to the wheels and would not accelerate. As I stepped on the gas the engine revved up but the vehicle was not accelerating. I thought it slipped out of gear. I put it in neutral then back into drive and still had the same problem. I put my flashers on to alert the truck that I was having issues. I pulled onto the shoulder and he passed me. I noticed the tachometer read between the 3 and 4 mark when I put my foot on the accelerator trying to speed up. However, the vehicle did not speed up at all. I was able to pull off the road onto a turnout area. The passenger in the front seat asked if any warning light came on. No lights of any sort came on. The temperature gauge was in the normal operating range. After the car stopped I turned off the ignition and opened my door and noticed flames coming from the bottom of the car. I immediately instructed the other three (3) passengers to immediately exit the car because of the flames. Luckily we were able to exit the vehicle and get a safe distance away to call 911 for assistance. Unfortunately the fire continued to burn and engulfed the car. Black smoke started to appear. The fire department showed up and extinguished the fire. We watched helplessly while our car and possessions went up in smoke. We contacted Subaru and filed a compliant. They took their time and eventually sent their qa team to inspect what was left of the vehicle. They finally sent us an email stating they could not find the root cause of the fire because the fire damage was too intense. We bought this vehicle new just two years prior and it only had about 30k miles and had all the factory recommended services at the dealership. The vehicle is under warranty.