My j7 prime from t-mobile has been suffering from battery drain since the oreo update last September. It charges until 88% & just hangs there for hours. My phone is a lil bit older than 2 years but there's nothing wrong with it besides this. I would appreciate any positive feedback for this inquiry.
Have you tried removing the battery, and then restarting the device?
Since steroids toot can try:
1: cleart the cache partition
2: back up your data and factory reset
3: take the battery out, press power for 10 seconds and replace the battery.
And 4: Getty a new battery as your office is over 2 years old and batteries die.
I hope this solves your issue.