Hello, I’m building a health-related app for both watchOS and iOS, which needs to monitor certain health data (e.g., heart rate, active energy). Before updating to watchOS 26, the queries worked reliably without any issues. However, after adapting to watchOS 26, some users have reported that health data updates stop being delivered. What I’ve observed: HKObserverQuery with enableBackgroundDelivery is set up normally. On WatchOS 26, the query sometimes stops delivering updates entirely after a certain point, and once an update is missed, it may stop delivering further updates completely. Restarting the Apple Watch temporarily restores delivery, but the problem reoccurs after some time. This makes background health data monitoring unreliable for my app. Here’s a simplified version of the code we are using: guard let heartType = HKObjectType.quantityType(forIdentifier: .heartRate) else { return } let query = HKObserverQuery(sampleType: heartType, predicate: nil) { query, completionHandler, error in if let error = error { logEvent("Observer error: \(error.localizedDescription)") return } logEvent("Heart rate changed") MyNotificationManager.shared.sendNotification() // Send a local notification completionHandler() } healthStore.execute(query) healthStore.enableBackgroundDelivery(for: heartType, frequency: .hourly) { success, error in if success { logEvent("Background heart rate delivery enabled") } else { logEvent("Failed to enable background heart rate delivery: \(error?.localizedDescription ?? "Unknown error")") } } Could you please clarify: Is this a known issue with HKObserverQuery and enableBackgroundDelivery on watchOS 26? Are there any recommended workarounds or best practices to ensure continuous background delivery of health data? Thank you in advance for your help.

We are developing a health app that relies on HKObserverQuery and BackgroundDelivery to monitor Heart Rate data. On watchOS 10.6 and 11.6 , these data updates are typically delivered reliably every 8–12 minutes, occasionally exceeding 12 minutes, but generally not longer than 15 minutes. This frequency has been sufficient for the real-time data requirements of our app. However, after adapting our app to watchOS 26, we noticed that HKObserverQuery triggers much less frequently, with longer and very inconsistent intervals. This issue has had a major impact on our product: data collection for essential features is unreliable, resulting in a greatly diminished user experience on watchOS 26 and making the app essentially useless from the user’s perspective. Observed Behavior: HKObserverQuery and BackgroundDelivery are extremely unstable, with trigger intervals frequently exceeding 15 minutes, and sometimes even 20 minutes. When the user is sedentary, intervals become even longer; there are cases where no heart rate or active energy updates are delivered for 30 minutes, or even over 1 hour. Request for Support and Guidance: Have there been any changes to the HKObserverQuery background delivery mechanism on watchOS 26, specifically for Heart Rate and Active Energy data? If these changes are intentional system optimizations, could you provide guidance or recommended practices to ensure our app can reliably retrieve updates and maintain a smooth experience for users? Thank you for your support.