Test/review of Shockli IMR26650 5500mAh (Black) 2017
Maybe temperature triggered, although a bit low I believe. PLB's 5.5Ah NiCoMn cell, surpasses both capacity and discharge ratings at the same time. Take that big brothers! 
Right now, PLB is ripping all of the remaining 26650 li-ion players a new one.
Cheers ^:)