What's wrong with WeChat message without sound?

If you use a vivo phone, there is no prompt tone when WeChat receives the message:

1, enter WeChat-I-Settings-New Message Reminder-New Message System Notification-New Message Notification-Voice-Select the tone;

2. Enter Settings-Sound (and Vibration) Settings to check whether the notification volume has been adjusted;

3. Go to Settings-Notification and Status Bar-Application Notification Management-WeChat to check whether notification is enabled;

4. Try to uninstall and reinstall WeChat;

5. Enter Settings-System Management/More Settings-Backup and Reset/Restore Factory Settings-Restore all settings (it is recommended to back up important mobile phone data before operation).