I am really unhappy that Google’s Android 7 started living with its own life against its user will. Android 7 will turn on and off Bluetooth connectivity on its own and scan the area itself, even that you turn off the Bluetooth device by hand. It looks that you have no control over your own phone anymore! Shame on you Google! Really poor design idea :-(
Update: I have reported this issue to Google Security Team, they got interested, so this does not seem to be a “standard feature”.. maybe a phone design flaw or firmware/microcode bug..