Any One face this prob. S8/S8+ userMobile turn off automatically when
battery level goes down below 20% .. after update November security
patch then i faced this issue only 2 times.
1st reboot ur mobile checked all thing if its not working. remove ur sd
card try it on another mobile & checked it. sd card ok or not. if its
working then backup ur all data, format ur sd card then put it in ur
mobile. if its showing normally move ur...