Today when I checked my notifications, one mentioned something about lock screen (can't remember exactly). I clicked on it to learn more, and now I have no sound. I've checked the usual settings, and they show that the sound is on.
Go to Settings and notifications then Advanced settings and notification history. You can see any notifications you missed. An easier way is download Samsung Good Lock and Notistar module to see notifications history easier. Also in Good Lock download Nice Catch module to find any unexplained issues.
In the members app go to support and do a diagnostic test. (Reposted after mistakenly deleting.)
