Bought my 2019 BHS April 20, 2018. Camped three times in it, plus 2 "dry runs" with the 2 grandkids in the backyard.
The switch on the water heater accessible on the outside is to power the electric element. Make sure it doesn't get powered with no water in the heater! Lots of horror stories here on that.
The inside water heater switch is to run it on propane. Make sure you opened your tank valve. It can take a while to purge your gas lines of air. Especially for the fridge. Most recommend using the stove top burners to help with the air purge the first time. If no ignition occurs with a couple seconds, your water heater (or fridge) is designed to stop trying for safety.
2019 Cherokee Wolf Pup 16BHS flipped axle
2019 Ford F-150 S-Crew 5.5 bed V8 w/tow package, TBC, Tow Mirrors, 3.55, 7000# GVWR, 1990#CC
Husky Centerline TS WDH 400-600# spring bars