How to turn off the sound for the "Wi-Fi has no internet access" notification on Android 7.0?
Thanks! It solved for me, when the notification popped up, I long press it few seconds and there's an option 'All categories' and 'Done' after pressing All categories it took me to the System settings as in the picture, and on Network alerts I disabled the Floating notification and Sound, The annoying notification were never to be seen again.