When I set my S9 to vibrate or mute I still get sound notifications from my messages. With my S6 and S7 when I turned off my phone sounds it applied to all sounds, is there a setting for this or is the feature gone?
I am having the same issue on my S8+, phone set to vibrate but intermittently making a sound on default Samsung sms app and WhatsApp.
It's very frustrating as I can't take my phone into meetings.
My friend has the same phone, the settings are The same and he doesn't have the same issue.
I have tried a factory reset, and took the phone to a Samsung shop, they checked it over and couldn't see an issue, they did a reset via their computer but I still have the issue.
This youtube video fixed my problem.
Go to: Settings> Accessibility> Notification Reminder > Slide to Off
It keeps reminding us we have unread notifications!! Very annoying, I realize I am ignoring people.