Why is Apple's mobile phone receiving information delayed?

The most obvious reason for the delay of Apple's mobile phone notification is the network problem. When the network signal is unstable or the network connection is disconnected, the notification function of the mobile phone will be greatly affected and there will be a delay.

There may be some problems with Apple's mobile phone operating system, especially after the system is updated, some users may have delayed notification. This is because some applications need to be re-adapted and adjusted after the system is updated, which leads to the delay of notification.