I have erased all my apple watch and iphone to factory settings as recommanded on many articles, this does not change anything 100% to 10% in one night without touching it, I have taken an appointment at Apple Store to change the device. I don’t want to pay the cost of this buggy update

iPhone XS Max, 1 month old and battery is dropping to 30% in 1-2h without even touching it, Apple need to fix this IOS bull**** really soon !