Why doesn't the mobile phone advertising notice ring OPPOA53?

The mobile phone advertising notification ringtone may not ring for the following reasons:

1. Check whether the phone has turned on the mute mode: setting, sound and vibration, mute mode, and turned on the complete mute function;

2. Check whether the mobile phone has turned on the Do Not Disturb mode: set the Do Not Disturb mode;

3. Has the mobile phone turned off the switch of the notification center: setting, notification center, information, notification authority, status bar display and screen lock display (currently, only the coloros2. 1 system has this function);

4. Whether to turn off information notification in mobile phone information settings: information, settings and information notification;

5. Check whether the phone has opened the contact. This link does not remind you: contact. Contact information. This link won't remind you.