On my Sony Xperia Z3V, recently upgraded to Android 5.1.1, I began using Verizon Messaging Plus. When I get a text, my phone vibrates, a notification icon appears for three seconds, and then disappears. So if I miss the vibration, there is no notification icon to see, and the only way I know if I've gotten a new text message is to open the app. Does anyone know why this is happening? I've checked the app itself, and all system settings, and the app has all the permissions it needs to give notifications.