This looks like a software issue. Check out doing a factory reset after backing your stuff up to micro SD etc ES fileExplorer:appBackup etc then reset. Battery stats bin can be hacked or altered between OS and updates or FOTA firmware Over The Air updates that can seriously inhibit functionality (think @pell a few years ago). So try that. Or if you have root, try battery stats erase via root app.
https://forum.xda-developers.com/showthread.php?t=1099808
-nand26