FWIW, not only have I noticed that issue with non-stock chargers (wall AND car) but also with an older usb extension I put in-line between the stock wall charger and stock usb cord. I'm not sure if that usb extension was even a "2.0" cable or if the pinouts are incorrect, etc... I had it laying around. But I tried a different usb extension and it works fine and charges fast.
Kind of just illustrates that our phones are quite picky with what power we supply them. I also had to ditch a car charger that was rated at 1.0 amp supposedly because of this drain you speak of.
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