Not uncommon. Dealer tech who assembled the tractor, loader, and backhoe got in a rush. When the power beyond and pressure hoses are installed backwards, 3ph won't work. Done it myself dozens of times. Why? Instructions for installing the loader have the hoses labeled green, gray, and IIRC orange. They come preinstalled (but loose) on the FEL valve, so all you have to do (supposedly) is match the colors and go with it. Well that's great as long as the manufacturer puts the correct hoses on the correct ports of the FEL valve. A lot of times they're in the right places, but they painted the colors incorrectly on the hose fittings, so when tech attaches to the tractor, 2 are backwards. I've taught all the other techs doing assembly to always check the 3ph to see if it works after a FEL install. If not, switch the hoses. It's an easy thing to do (screwing it up and fixing it). Being switched won't hurt anything in the system, either, aside from making an owner lose confidence in their selling dealer. But trust me, from a dealer's standpoint, we aren't perfect either. I wish we were and we certainly do our best to try, though.