I recently upgraded to an Android 11 smartphone and for some reason my default notification sound had changed and I could not change the default notification sound in the Yahoo Mail app settings.
I found a way to fix this temporarily until Yahoo issue a fix themselves (assuming it is not a Pro feature option only now).
These instructions are for Android 11 specifically but these may be the same for Android 9 and 10 (I cannot clarify as I don't own a device with these versions of Android):
1) Go to "Settings"
2) Scroll down and tap "Apps"
3) Scroll down and tap "Yahoo Mail"
4) Tap on "Notifications"
5) Under "Other" tap on each listed option below and then tap on "sound" and select the sound you wish to hear. They will be set to "Default notification sound" but you can change them to fix it for now :)
- Emails from people
- Deals emails
- Travel emails
- Parcel delivery emails
- Other emails
- Reminders
- General alerts
- Miscellaneous
- Account security alerts
