I implemented this to receive updates for specific data types and keep the latest daily information up to date. However, for some reason, it only works for a while before stopping completely. Background Delivery internal func backgroundDeliveryForReadTypes(enable: Bool, types: Set<HKQuantityType>) async { do { if enable { try await statusForAuthorizationRequest(toWrite: [], toRead: types) for type in types { try await healthStore.enableBackgroundDelivery(for: type, frequency: .daily) } } else { for type in types { try await healthStore.disableBackgroundDelivery(for: type) } } } catch { debugPrint("Error enabling background delivery: \(error.localizedDescription)") } } HKQueryAnchor internal var walkingActivityQueryAnchor: HKQueryAnchor? { get { if let anchorData = UserDefaults.standard.data(forKey: "walkingActivityAnchor") { return try? NSKeyedUnarchiver.unarchivedObject(ofClass: HKQueryAnchor.self, from: anchorData) } return nil } set { if let newAnchor = newValue { let anchorData = try? NSKeyedArchiver.archivedData(withRootObject: newAnchor, requiringSecureCoding: true) UserDefaults.standard.set(anchorData, forKey: "walkingActivityAnchor") } else { UserDefaults.standard.removeObject(forKey: "walkingActivityAnchor") } } } HKAnchoredObjectQuery internal func observeWalkingActivityInBackground( _ start: Bool, toRead: Set<HKQuantityType>, completion: @escaping @Sendable (Result<WalkingActivityData?, Error>) -> Void ) { if start { guard (walkingActivityQuery == nil) else { return } let predicate = getPredicate(date: Date()) let queryDescriptors = toRead.map { HKQueryDescriptor(sampleType: $0, predicate: predicate) } let handleSamples: @Sendable (HKAnchoredObjectQuery, [HKSample]?, [HKDeletedObject]?, HKQueryAnchor?, Error?) -> Void = { [weak self] _, samples, _, newAnchor, error in guard let self = self else { return } if let error = error { completion(.failure(error)) return } guard let samples = samples, !samples.isEmpty else { completion(.success(nil)) return } Task { self.walkingActivityQueryAnchor = newAnchor let activity = await self.getWalkingActivity(date: Date()) completion(.success(activity)) } } let query = HKAnchoredObjectQuery( queryDescriptors: queryDescriptors, anchor: walkingActivityQueryAnchor, limit: HKObjectQueryNoLimit, resultsHandler: handleSamples ) query.updateHandler = handleSamples healthStore.execute(query) walkingActivityQuery = query } else { if let query = walkingActivityQuery { healthStore.stop(query) walkingActivityQuery = nil } } } WalkingActivityData private func getWalkingActivity(date: Date) async -> WalkingActivityData { async let averageHeartRate = try await self.getAverageHeartRate(date: date) async let steps = try self.getStepCount(date: date) async let durationMinutes = try self.getTotalDurationInMinutes(date: date) async let distanceMeters = try self.getDistanceWalkingRunning(date: date, unit: .meter()) async let activeCalories = try self.getActiveEnergyBurned(date: date) return await WalkingActivityData( date: date, steps: try? steps, activeCalories: try? activeCalories, distanceMeters: try? distanceMeters, durationMinutes: try? durationMinutes, averageHeartRate: try? averageHeartRate ) } Example of getAverageHeartRate func getAverageHeartRate(date: Date) async throws -> Double? { let type = HKQuantityType(.heartRate) _ = try checkAuthorizationStatus(for: type) guard let heartRate = try await getDescriptor( date: date, type: type, options: .discreteAverage ).result(for: healthStore) .statistics(for: date)? .averageQuantity()?.doubleValue(for: HKUnit.count().unitDivided(by: HKUnit.minute())) else { return nil } return Double(String(format: "%.2f", heartRate)) ?? 0.0 } Descriptor & predicate internal func getPredicate(startDate: Date, endDate: Date) -> NSCompoundPredicate { let predicateForSamples = HKQuery.predicateForSamples(withStart: startDate, end: endDate) let excludeManual = NSPredicate(format: "metadata.%K != YES", HKMetadataKeyWasUserEntered) return NSCompoundPredicate(andPredicateWithSubpredicates: [predicateForSamples, excludeManual]) } internal func getDescriptor(startDate: Date, endDate: Date, type: HKQuantityType, options: HKStatisticsOptions) -> HKStatisticsCollectionQueryDescriptor { let calendar = Calendar(identifier: .gregorian) let anchorDate = calendar.date(bySetting: .hour, value: 0, of: startDate)! var interval = DateComponents() interval.day = 1 return HKStatisticsCollectionQueryDescriptor( predicate: HKSamplePredicate.quantitySample(type: type, predicate: getPredicate(startDate: startDate, endDate: endDate)), options: options, anchorDate: anchorDate, intervalComponents: interval ) } Implementation public func observeWalkingActivityInBackground(_ start: Bool, toRead: Set<HKQuantityType>, memberID: String) { observeWalkingActivityInBackground(start, toRead: toRead) { [weak self] result in guard let self = self else { return } } }

I’m trying to use BGProcessingTaskRequest to fetch step data in the background and send it. However, when I combine BGProcessingTaskRequest, HKObserverQuery, and healthStore.enableBackgroundDelivery, the results sometimes return zero. When I don’t schedule the BGProcessingTaskRequest, the data retrieved using HKObserverQuery and HKSampleQueryDescriptor is correct. // Register Smart Walking Sync Task func registerSmartWalkingSync() { #if !targetEnvironment(simulator) BGTaskScheduler.shared.register(forTaskWithIdentifier: BGTaskIdentifier.smartwalking.rawValue, using: nil) { task in guard let task = task as? BGProcessingTask else { return } self.handleSmartWalkingSync(task: task) } #endif } func scheduleSmartWalkingSync(in seconds: TimeInterval? = nil, at date: Date? = nil) { let newRequest = BGProcessingTaskRequest(identifier: BGTaskIdentifier.smartwalking.rawValue) newRequest.requiresNetworkConnectivity = true newRequest.requiresExternalPower = false if let seconds = seconds { newRequest.earliestBeginDate = Date().addingTimeInterval(seconds) } else if let date = date { newRequest.earliestBeginDate = date } do { try BGTaskScheduler.shared.submit(newRequest) debugPrint("✅ [BGTasksManager] scheduled for Smart Walking Sync") } catch { FirebaseConnection.shared.recordException(error) debugPrint("❌ [BGTasksManager] error: \(error)") } } // Handle Smart Walking Sync Task func handleSmartWalkingSync(task: BGProcessingTask) { debugPrint("🔄 [BGTasksManager] sync \(task.identifier) sync started") scheduleSmartWalkingSync(in: SYNC_SMARTWALKING_TIME_INTERVAL) let queue = OperationQueue() let operation = HealthActivitiesOperation() operation.completionBlock = { Task { do { try await operation.sync() task.setTaskCompleted(success: !operation.isCancelled) debugPrint("✅ [BGTasksManager] sync \(task.identifier) completed successfully") } catch { FirebaseConnection.shared.recordException(error) task.setTaskCompleted(success: false) debugPrint("❌ [BGTasksManager] sync \(task.identifier) error: \(error)") } } } task.expirationHandler = { operation.cancel() } queue.addOperation(operation) } // MARK: - HealthKit Background Delivery internal func enableBackgroundDeliveryForAllTypes() async throws { for type in allTypes.filter({ type in type != HKQuantityType(.heartRate) }) { try await healthStore.enableBackgroundDelivery(for: type, frequency: .daily) } debugPrint("✅ [HealthKitManager] Enable Background Delivery") } internal func observeHealthKitQuery(predicate: NSPredicate?) async throws -> Set<HKSampleType> { let queryDescriptors: [HKQueryDescriptor] = allTypes .map { type in HKQueryDescriptor(sampleType: type, predicate: predicate) } return try await withCheckedThrowingContinuation { continuation in var hasResumed = false let query = HKObserverQuery(queryDescriptors: queryDescriptors) { query, updatedSampleTypes, completionHandler, error in if hasResumed { return } if let error = error { continuation.resume(throwing: error) } else { continuation.resume(returning: updatedSampleTypes ?? []) } hasResumed = true completionHandler() } healthStore.execute(query) } } internal func getHealthActivity(by date: Date, predicate: NSCompoundPredicate, sampleTypes: Set<HKSampleType>) async throws -> HealthActivityData { var data = HealthActivityData(steps: 0, calories: 0, distance: 0.0, distanceCycling: 0.0, totalDuration: 0, date: date, heartRate: nil) for sampleType in sampleTypes { guard let quantityType = sampleType as? HKQuantityType else { continue } switch quantityType { case HKQuantityType(.stepCount): let stepCount = try await getDescriptor( date: date, type: quantityType ).result(for: healthStore) .statistics(for: date)?.sumQuantity()?.doubleValue(for: HKUnit.count()) data.steps = stepCount ?? 0.0 // Calculate total duration using HKSampleQueryDescriptor let totalDurationDescriptor = HKSampleQueryDescriptor( predicates: [.quantitySample(type: quantityType, predicate: predicate)], sortDescriptors: [SortDescriptor(\.endDate, order: .reverse)] ) let stepSamples = try await totalDurationDescriptor.result(for: healthStore) data.totalDuration += stepSamples .reduce(0) { $0 + $1.endDate.timeIntervalSince($1.startDate) } / 60.0 default: debugPrint("Unknown quantity type") } } return data }