where do you live ?
Here in France (Europe ?) in 6 first month they must prove their point. you can do anything on software, it does not void hardware warranty...
But yes, it is hard to make them accept they must take it in warranty.
Did you try yo restore default ROM with Kies or Odin and see what happens ? (KNOX is still at 1, but ROM clean and unrooted)
Motorola RAZR HD (XT925)
Samsung Galaxy Tab S 4G/LTE (SM-T805)
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