I had an experience like this with them recently too--In order to save $15, I bought a part for my Whirlpool washer on Amazon. It was the in-flow controller which the water hoses hook in to. I ordered it from "Sold and Fulfilled by Amazon" which used to be my mark of a decent product (or at least I know I'll be able to get a refund if it has issues directly from Amazon). It arrived in unbranded cardboard, but the plastic wrapper did have "Maytag" stamping. Unfortunately my washer refused to recognize it despite it being extremely basic in design (a couple servos and a tiny switching board connected to some plastic tubes for water inlets). I requested a refund from Amazon which happened with in hours and went down to a local appliance repair place and paid the extra $15 for another.
The one from the local shop was not wrapped in plastic, but it was in Maytag branded cardboard with part-number and SKU. Took it home and compared it to the Amazon part which I hadn't yet boxed up and the Amazon part was visibly of lower quality plastic (edges were poor, you could see where welds had been done at the corners) and the circuit board with the switching components was completely different despite having the same molex-type connector. BOTH units had the same part-number molded in to the plastic in the same spot, yet the actual Maytag version I got locally worked instantly the first time.
The one from the local shop was not wrapped in plastic, but it was in Maytag branded cardboard with part-number and SKU. Took it home and compared it to the Amazon part which I hadn't yet boxed up and the Amazon part was visibly of lower quality plastic (edges were poor, you could see where welds had been done at the corners) and the circuit board with the switching components was completely different despite having the same molex-type connector. BOTH units had the same part-number molded in to the plastic in the same spot, yet the actual Maytag version I got locally worked instantly the first time.