Ughh....I guess it's an update problem. I've tried many different solutions and none has worked. What is your firmware region if you don't mind me asking? XSG UAE?
performing a factory reset might refresh things up too, the battery starts to age just after 2 years of use, get used to it i guess. or if it's a software related problem, we might be lucky to get solution along with the next security patch, but first Samsung must know that we're facing this issue, so consider reporting it.
My phone is not even two years old yet. I did a factory reset and even flashed a different firmware, BLU UK and the problem is still there. Some people are saying that I need to wait a few days for the new update to "settle" down, but I don't know if a software needs to settle down lol I will wait few days and see what happens