Ring doorbell 2 not notifying phone

New user here - Hi My Samsung S7 has stopped receiving notifications after a month of working properly. It now receives a banner at top of phone screen saying something like "Somone is at the door" if phone is already open. If I click on this it opens the Ring App. But I do not receive any audible sound on the phone. (The Ring Chime Pro does sound). The stock answer seems to be uninstall the app and re-install. I have done this but no different. Also turned on-off Samsung S7. ANyone any ideas why this has stopped working.