Sorry to here about it biilt, that NPT, (called here) stuff can be prone to fail. It's used on boats as well and there is NO margin of error when it comes to install.
Some are good for 2 days, 2weeks, or two years, THAN something happens.
PEX, NPT, is a cost effective way to plumb a house, boat, RV, etc,... Its like a chain, only as strong as it's weakest link, joint, fitting, coupler, or bend.
Take Care,
tw