[Geoff Bacon]

Try googling "turn off all notifications android do not disturb"

On my tablet, I went to Settings | Notifications and selected "all apps" - this moved all the individual app sliders off. You probably don't want to do this (I was hoping it would just be a master suppress rather than changing the settings).

The "Do not Disturb", on my tablet, is in the Sounds settings - this "Mutes all calls and alerts, except for your custom exceptions". I'm guessing tht if you enable this it will prevents dings etc but I've no idea if it also suppresses popups (which could cause you a problem if they cover notes that you are about to play).

Suggest you enable "Do Not Disturb" and then send it something a whatapps message or an email to see if it displays a notification

Geoff