I just got a new Samsung Galaxy S9, I love using the Verizon Messaging App. I was using the app up to a few days ago when it quit giving me notifications. I went through all the settings but still no notifications. I uninstalled the app and went and reinstalled the app still not working. I love the driving feature as well which i used for one day.
Making sure that you get your message notifications is very important. I want to do all I can to help resolve this. Have you checked in the Google Play Store to verify that the Verizon Messages application is up to date? It is also beneficial to verify that the device itself is full up-to-date: http://spr.ly/66051PRr5
Please let us know if this helps, or if the issue persists!