Who I have the same questioned this solution

Havent checked which software it is at yet but ended up just doing complete reset. (With phone off press and hold volume down and power together until a new screen pops up. You will see factory reset listed. Click that. It may reboot several times like mine did. If google did a backup of your settings and apps when you start to setup the phone again it will give you that option to restore it)

We shall see.