Live Activity PushToken Not Callback

I have start new live activity with push notifications,but sometimes this code"activity.pushTokenUpdates" can not callback to me,so I can't update the activity with push notifications. And I already click “Allow” button in my live activity widget.How can I solve this problem. Here are my code：

fileprivate func observeLiveActivityForRemoteCreate() {
        // obverser pushToStartToken
        Task {
            if #available(iOS 17.2, *) {
                var beforeToken = ""
                for await pushToken in Activity<HLPlatformActivityAttributes>.pushToStartTokenUpdates {
                    let pushTokenStr = pushToken.map{String(format: "%02.2hhx", arguments: [$0])}.joined()
                    // avoid send duplication
                    if beforeToken == pushTokenStr {
                        return
                    }
                    beforeToken = pushTokenStr
                    
                    // send pushToStartToken to service
                    await HLPlatformLiveActivityBridge.registerLiveActivity(withAttributesName: self.activityAttributesName, pushToStartToken: pushToken, seq: seqCreate(), pushType: .jPush)
                }
            }else {
                // Fallback on eralier versions
            }
        
        // obverser live activity update
        Task {
            for await activity in Activity<HLPlatformActivityAttributes>.activityUpdates {
                if let businessLiveActivityId = activity.attributes.businessLiveActivityId, let liveActivityId = activity.attributes.liveActivityId {
                    Task {
                        
                        var beforeToken = ""
                        for await pushToken in activity.pushTokenUpdates {
                            // here the problem：sometimes pushToken not update to me
                            let pushTokenStr = pushToken.map{String(format: "%02.2hhx", arguments: [$0])}.joined()
                            // avoid send duplication
                            if beforeToken == pushTokenStr {
                                return
                            }
                            beforeToken = pushTokenStr
                            // send pushToken to service
                            
                        }
                    }
                    
                    Task {
                        for await stateUpdate in activity.activityStateUpdates { 
                            if stateUpdate == .active {
                               // live activity create 
                            }
                        }
                    }
                }
            }
        }
    }