I've had my Galaxy S8 for 4 months now and fast charging was working perfectly. Today when I plugged in my phone, it said "Fast Charging" for a second, then stopped charging all together, and finally started charging normally, I tried another charger, another plug, factory resetting my phone, wiping its cache but it's still like this.
Considering the troubleshooting you tried, definitely reach out to Samsung directly via Phone (1-800-726-7864) or through the Samsung Plus App to set up an evaluation and repair. Naturally you can also reach out to your carrier to see if they have a different option you might like more or maybe someone here in the Community has some other ideas!
Be sure to click " ✓ Accept as Solution" when you find an answer that works for you.
My s8 does not have any charging issues but its having a very strange problm. All my calls gets diverted on my another ph no. Automatically when d phone is not reachable. Even after cancelling calls transfer by dialing ##002# it got ok for few minutes then again calls got diverted.
On complaining to airtel ,D 3rd day the divert problem solved. But den the phone is not reachable for long hours.and as and when i cancel d diverts ..d ph starts working..its a new handset and such a bad performance.