I recently found out that after the update to nougat, the phone doesn't
lock properly after pushing the power button. Now it can be unlocked
just by clicking on the power button to activate the screen and swapping
on the lock screen. Nor the pin or f...
Try this: once the phone reaches 90% stop using the mobile data
connection and unplug the charger. Reconnect the charger keeping the
mobile data connection off. It works for me. I hope Samsung will fix
this bug soon.