I have the same issue. Fast charging was working before Oreo upgrade. After the upgrade, it doesn't work anymore. Factory reset doesn't help. Bought a new samsung original charger. Still no fast charge after oreo update. This is probably gonna be my last samsung phone.
I have tried all suggested fixes to no avail. The extra large battery on my s7 active no longer gets me through the day and now takes over 8 hours to charge. I got this phone new, not refurbished, less than a year ago. I really need this fixed, thanks.
I have the same issue. Fast charging is not working. Could you please have a look at this? It must be a software issue. It is very annoying having to have the phone plugged in 5-6 hours every day. Any assistance is highly appreciated.