Could be the fitting has just backed off the faucet threads. I might suggest (with the pump turned OFF) disconnecting each water line from the faucet, wrapping the 1/2" pipe threads with some Teflon tape (start @ bottom & work up about 3/4" wrapping in the directions the threads run), and then reconnecting water lines. If that doesn't work, then it's probably the pex fitting itself - probably the clamp is too loose. That's why I hate pex fittings. While it's still under warranty, I'd take it to the dealer & hope you can make it leak while you're there. Once it's out of warranty, I'd switch as many fittings as you can reach over to "Shark-bite" (or similar) fittings. They're a little pricey. but you only need a few. They go on in seconds (without any special tools), and in the 10 years I've been using them, I've never had one fail.
2013 Eagle 266RKS
2011 Ford F-150 w/3.5L Ecoboost & H.D. Tow Package