~ Turn on push notifications in the message centre of the Apple device. 

~ The firewall of the modem prevents connection with APNS (Apple Push Notification Server). Open up listening ports on the router; check the Apple support site for this. https://support.apple.com/en-us/HT203609 

If you have any additional questions, you can always contact us via this website.

Please state the complaint clearly so we can help you.