I think the most likely explanation is that the phone’s settings were being backed up to the Google account (which is what the system’s Backup feature is supposed to do). Google Activity keeps track of which app accesses the Google account that the phone is associated with.

How do I find hidden settings on android?

On the top-right corner, you should see a tiny settings gear. Press and hold that little icon for about five seconds to reveal the System UI Tuner. You will get a notification that says the hidden feature has been added to your settings once you let go of the gear icon.

What does used android mean?

Android is the program your device uses. Like your pc might use Windows, or iPad uses apple…. Don’t mess with it.