We had a similar thing happen on our maiden trip with our 2017 TT purchased new in Nov 2016. Suburban 6 gallon also. We were in the Keys and it quit working on gas, similar to what you described, although I don't remember a gas smell. Still worked on electric.
We took it to the dealer and the fix was a new circuit board. Sorry I don't know enough to tell you what part exactly since I did not fix it. I know that was the problem because when we picked it up I asked to review all repairs and verify they were done. At first the HWH did same as before so they had not repaired it properly ( big surprise lol ) . Two techs got on it and replaced a board in it in just a few minutes and now it works fine.
Maybe someone here with more knowledge can tell you how to check the board out etc. Good luck