部分iOS设备静默推送通知无法正常工作问题求助

测试设备情况 #

• 静默推送正常：iOS 16.5.1 (c)，iPhone Xs
• 静默推送失败：iOS 15.3.1，iPhone Xr

问题现象 #

两台设备均可正常接收普通提醒通知，但iOS 15.3.1的iPhone Xr在接收静默推送后，Swift项目中没有任何日志输出。

已完成的排查项 #

• content-available已设置为1
• 应用未处于终止状态，当前为前台或后台挂起状态
• 发送普通通知时，Swift项目可正常生成日志，设备接收正常
• 推送证书未过期（若证书存在问题，普通通知也无法正常接收）
• 设备未开启省电模式，且已在应用设置中开启“后台应用刷新”选项
• 两台设备均处于充电状态
• 应用已开启Background Modes权限，包含Remote Notifications、Background Fetch、Background Processing

CloudKit仪表板状态 #

发送静默推送后的状态：

Swift项目AppDelegate代码 #

import SwiftUI
import UIKit
import UserNotifications

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { granted, error in
            if granted {
                DispatchQueue.main.async {
                    UIApplication.shared.registerForRemoteNotifications()
                }
            }
        }
        return true
    }

    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        let tokenParts = deviceToken.map { data in String(format: "%02.2hhx", data) }
        let token = tokenParts.joined()
        print("Device Token: \(token)")
    }

    func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
        print("Failed to register: \(error)")
    }
    
    func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
        logInfo("Received Push Notification: \(userInfo)")

        if let aps = userInfo["aps"] as? [String: AnyObject], aps["content-available"] as? Int == 1 {
            logInfo("This is a silent push notification")
            //DO SOME WORK
            completionHandler(.newData)
        }

        completionHandler(.newData)
    }
}

内容的提问来源于stack exchange，提问作者Ozgur Baykal