As per your concern, we would request you to kindly perform the following steps to resolve your issue.
To change the notification sound for each app on the device, the option should be enabled first in the notification settings, then you can now see and set the relevant options for each app. Please follow these steps:
1) Activate 'Manage notification categories for each app'.
Path: Settings > Notifications > Advanced settings > turn On 'Manage notification categories for each app‘
This will allow you to see the 'Notification categories' option in the each app settings. Then you can change notification sound in each app settings. To seen and change the sound, you need to set the type to ‘Alert’ option.
2) Change the notification sound: Path① : Notification panel > press and hold the pop-up of the app > Settings > Notification categories > select the category > Sound
Path② : Settings > Apps > select the app > Notifications > enable Allow notifications > Notification categories > select the category > Sound [Enable 'Manage notification categories for each app'].
In case the issue still occurs, kindly report the problems with a log file. To share a log file, click on the Samsung Members Application ((Open Samsung Members Application > Support> Tap on send feedback> Choose Composer> Select error report> select the appropriate issue category> Type your query and send.)
