J7 Prime has a cheap low cost outdated model fingerprint sensor, it takes more time to scan and has precision issues. Can't be fixed, this is how Samsung reduces cost on budget devices. Skipping all the sensors, using cheap thin glass, low guage meta...
Get the battery replaced. J7 Prime batteries are getting worn out within 6-10months of use, its of pathetic quality. It's the battery problem. I had the same issue. No software update could fix it for 7months. Replaced the battery and everything work...
