Por que razão não é possível receber notificações de mensagens depois de bloquear o ecrã?

To troubleshoot phone settings:

1.”Enable push notification switch”
2.”Allow background wake-up
3.”Auto-start app”
4.”Disable background refresh in low battery optimization”.
5.”Automatically close messages when ‘Do Not Disturb’ is enabled.”
6.”Reduce push notifications during sleep mode.”
7.”Optimize network when screen is off: Automaticallydisconnect network and background functions when the screen is off. These settings are generally similar across most Android phones