'Notification Service Extension Not working
Notification is not being displayed when I send mutable-content:1 with push payload neither it hits the breakpoint inside the Notification service extension, although without mutable-content push is being displayed, also Notification content extension is working fine. I did not modify the code inside the Notification service extension it's the default generated by the Xcode. Am I missing something while creating a notification service extension or it might be the issue with the device setting? I have tested on the same device a few days ago and the notification service extension was working fine.
Below is my code for service extension
import UserNotifications
class NotificationService: UNNotificationServiceExtension {
    var contentHandler: ((UNNotificationContent) -> Void)?
    var bestAttemptContent: UNMutableNotificationContent?
    override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {
        self.contentHandler = contentHandler
        bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)
        if let bestAttemptContent = bestAttemptContent {
            // Modify the notification content here...
            bestAttemptContent.title = "\(bestAttemptContent.title) [modified]"
    
           contentHandler(bestAttemptContent)
        }
    }
    override func serviceExtensionTimeWillExpire() {
        // Called just before the extension will be terminated by the system.
        // Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.
        if let contentHandler = contentHandler, let bestAttemptContent =  bestAttemptContent {
            contentHandler(bestAttemptContent)
        }
    }
}
edit 1: below is my push payload
{  
   "aps":{  
      "sound":"default",
      "mutable-content": 1,
      "category": "myCategory",
      "alert":{  
         "body":"this is a custom push",
         "subtitle":"subtitle of the push",
         "title":"Push Test"
      }
      
   }
}
edit1: The problem seems on that particular device running on 10.2.1, I checked with other device running on 10.2, it was triggering the Notification service extension.
Solution 1:[1]
Finally I was able to resolve the issue. I am not sure what was causing the issue but after some experiments I realised that not only my service extension but all other installed app's service extension was not working and when sending the push payload with "mutable-content: 1, Notification was not displayed. After rebooting the device it started working fine. I was using iPhone 6s.
Solution 2:[2]
Deployment target of your NotificationServiceExtension can also be a reason.
In my case, I was testing on Device running on iOS 12.4 while target version of my NotificationServiceExtension was 14.1. I Just changed my NotificationServiceExtension targeted version to 12.4 it Worked.
Solution 3:[3]
In my case it ended up being my extension using too much memory.
Console.app was only showing that Springboard was killing the app with an error like:
CMSessionMgr- CMSessionMgrHandleApplicationStateChange: CMSession: Sending stop command to _ with pid '_' because client is not allowed to play in the background AND does not continue AirPlaying video when device locks
I thought something was wrong with the entitlements or something like that, but once I debugged it I saw that it was iOS killing the process for taking too much memory. Once I fixed that bug, the extension was kept alive until I called the callback.
Solution 4:[4]
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source | 
|---|---|
| Solution 1 | rahulk9 | 
| Solution 2 | Ashwani Kumar | 
| Solution 3 | NachoSoto | 
| Solution 4 | Blazej Kita | 

