My fifth wheel has pex fittings thru-out and over the years of beating and banging up and down the road 1 or 2 are gonna leak. This past weekend the toilet in the bunkhouse had a small leak but had the floor all wet. I loosened the pex fitting all the way and then re-tightened and leak was gone. End of last season carpet wet in living area, I worked my way in and up thru the entertainment center..... All the way to the ceiling and there it was, loose pex fitting... Re- tightend and all good.
I think it's good to check all the fittings every once in awhile,
Problem is I've had two leak that were behind a wall, luckily both inside the entertainment center to easy to get to.