Not defending or pointing the finger at any of the rv manufacturers. But, I'll bet money that if you look at any new rv, none will have teflon tape or joint compound. The new plastic fittings are either glued or compression fittings. I know my previous rv had bare fittings and I had to re-tighten a few several times. Just part of the rv adventure.
2014 Chevy CC Duramax 4X4 Long Bed
2017 Cedar Creek 36CKTS