Water leak

But you did use the outside kitchen water supply every time you sanitized to make sure the bleach/water mixture was in that line and then to bleed it out with fresh water, correct?

The connections to faucets will often vibrate loose or come loose from hot/cold expansion contraction.

Try tightening the connections (hot and cold) on both faucets.

The connections for our bathroom faucet would start leaking every 5th or 6th trip. After the second time, I took it apart and used teflon tape to seal it. Hasn't leaked since.

Lots of question to help you diagnose. Is your water pump on? It won't matter if you turn off city water if the pump is on you will still have pressure. Have you used the RV since winter? Start checking pipes in the bathroom and your outdoor kitchen. Even if you've never used them, pressured water will find it's way there. Pex is pretty resilient to cracks so I would check fittings on fixtures, the faucet housings, unions and connections etc. The dealer should certainly be willing to take a look at it. This is a brand new unit right?