Samsung
Silence Notifications from Individual Apps auf Samsung
When a single app keeps ringing or showing previews on the lock screen while you only want a quiet status bar icon, the app is still using its default notification behavior. Samsung One UI lets you adjust sound and lock-screen visibility separately for each app, without touching the phone's overall Do Not Disturb settings.
To mute one app, go to Tap on Settings ➔ Tap on Apps ➔ Choose an App ➔ Tap on Notifications. Inside the app's notification screen, pick the category you want to change with Choose a Category and set it to Set Silent.
Silent mode removes the sound and the pop-up on the lock screen but keeps the notification visible in the notification field at the top of the screen. This differs from disabling notifications completely, which removes the app from the status bar as well.
If several apps behave the same way, checking each one individually is slower than using a focus mode or a scheduled Do Not Disturb, which mutes everything except selected exceptions. Use the per-app method when you only want to quiet one specific source without affecting the rest of your notifications.