I am having this issue in my s8 plus since 4 days I did all possible thing I found on web like q-tip cleaning. Drying with air restart and changed charger and cable and did hard resetting through setting only ( couldn't do through recovery as it says...
if it supports wireless charge go for it if not. try plugging charger during switch on when Samsung logo appears first. warning ms. won't appear. or go for Samsung care.
