I'm reporting a critical Health data synchronization failure that began immediately after updating from watchOS 18 to watchOS 26.0.2 (stable release) and persists in watchOS 26.1 beta 2.
Bug Description:
Complete failure of Health data sync from Apple Watch to iPhone Health app. All health metrics are being captured and stored locally on the watch but fail to sync to the paired iPhone.
Affected Data Types:
Activity rings (Move, Exercise, Stand)
Heart rate measurements
Sleep tracking data
Workout data
All other HealthKit data points
Environment:
Device: Apple Watch Series 7
Initial failure: watchOS 26.0.2 (23R362) - stable release
Current: watchOS 26.1 beta 2 (23S5052c)
Paired iPhone: iPhone 17 Pro Max, iOS 26.1 beta 2 (23B5052c)
Bluetooth and Wi-Fi connectivity: Normal
Watch pairing status: Connected and functional for all other features
Reproduction:
Updated Apple Watch Series 7 from watchOS 18 to watchOS 26.0.2 on September 30, 2025
Health data sync ceased completely starting October 1, 2025
Issue persists after updating to watchOS 26.1 beta 2 and iOS 26.1 beta 2
Data remains stored locally on watch and is viewable in watch apps
Apple Watch appears as connected data source in Health app but no data transfers
Troubleshooting Performed:
Multiple device restarts (both iPhone and Apple Watch)
Bluetooth/Wi-Fi toggling and reconnection
Verified Privacy > Motion & Fitness > Fitness Tracking and Health enabled on both devices
Confirmed data source priority settings in Health app
Extended charging periods to allow background sync operations
Verified no Low Power Mode restrictions
Impact:
Critical functionality loss for primary Apple Watch use case. Unable to track longitudinal health data, breaking continuity of health records dating back to watchOS 18.
Feedback Submitted:
FB20533870 filed via Feedback Assistant with sysdiagnose from both devices
Questions for Engineering:
Is this a known regression in watchOS 26.0.2 or later builds?
Are there any watchOS 26.1 beta release notes addressing HealthKit sync issues that I should review?
Should I capture additional diagnostic data (e.g., specific console logs, HealthKit database states)?
Is unpairing/re-pairing expected to resolve this, or would that indicate a deeper architectural issue?
Additional Context:
Apple Watch appears in Settings > Bluetooth as connected
Can successfully change watch faces from iPhone
Notifications, Messages, and calls work normally
No previous sync issues prior to watchOS 26.0.2
Senior Apple Support advisor escalation completed; awaiting engineering review
This appears to be a regression introduced in watchOS 26.0.2. Any guidance on additional diagnostics or confirmation of a fix in upcoming builds would be appreciated.
Health & Fitness
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How do I add my hospital to the list of hospitals available on the Health Records on iPhone application?
We are using HealthKit in our app to synchronize step count data.
The data is correctly synced with the Health app, but the step count does not appear in the Fitness app (although workout data does).
Is there anything developers need to do to synchronize step count data with the Fitness app as well?
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.
Topic:
App & System Services
SubTopic:
Health & Fitness
Tags:
Health and Fitness
watchOS
HealthKit
Observation
I have a watchOS app with a connected iOS app using Swift and SwiftUI. The watchOS app should read heart rate date in the background using HKOberserQuery and enableBackgroundDelivery(), send the data to the iPhone app via WCSession. The iPhone app then sends the data to a Firebase project.
The issue I am facing now it that the app with the HKObserverQuery works fine when the app is in the foreground, but when the app runs in the background, the observer query gets triggered for the first time (after one hour), but then always get terminated from the watchdog timeout with the following error message:
CSLHandleBackgroundHealthKitQueryAction scene-create watchdog transgression: app<app.nanacare.nanacare.nanaCareHealthSync.watchkitapp((null))>:14451 exhausted real (wall clock) time allowance of 15.00 seconds
I am using Xcode 16.3 on MacOS 15.4
The App is running on iOS 18.4 and watchOS 11.4
What is the reason for this this issue? I only do a simple SampleQuery to fetch the latest heart rate data inside the HKObserverQuery and then call the completionHandler. The query itself takes less than one second.
Or is there a better approach to read continuously heart rate data from healthKit in the background on watchOS? I don't have an active workout session, and I don't need all heart rate data. Once every 15 minutes or so would be enough.
I'm trying to make a watchOS app that uses sleep data to wake users up when they enter lighter sleep stages. Apple has HealthKit, which exposes HKCategoryValueSleepAnalysis to view each stage throughout sleep, but unfortunately, this data is only written after the user wakes up.
I did some research and found that the Apple Watch’s sleep classifier is part of Apple’s private system process, and apps can’t access that model directly or as it’s running. So, there’s no way to “record” my own data stream and match it with Apple’s classification during the night.
Has anyone found a way to approximate or access live sleep-stage data in another way?
I’m thinking of combining CoreMotion (for movement) and heart rate data from a HKWorkoutSession to infer stages myself, but I’m wondering if there’s any Apple-approved or more accurate approach for this.
In other words, is there any way to use an Apple Watch to detect sleep stages accurately while the user is still asleep for the purpose of timing an optimal wake-up? Thanks
Current HealthKit APIs provide access to heart-rate data through queries, but not as a true real-time stream. This limitation prevents systems such as Mercedes-Benz ENERGIZING from dynamically adapting the vehicle environment — including light, sound, seat massage and climate — to the driver’s physiological state.
The ENERGIZING Coach developed by Mercedes-Benz uses continuous biometric feedback to enhance comfort, focus and safety by adjusting sensory stimuli based on live pulse data. Garmin wearables can already support this because they offer open Bluetooth Low Energy protocols. The Apple Watch, on the other hand, stores heart-rate data securely in HealthKit and makes it available through delayed write intervals. As a result, the current query mechanisms such as HKAnchoredObjectQuery or HKObserverQuery deliver updates with a latency of several seconds to minutes, which is too slow for the type of sub-second reaction required by driver-assistance or wellness systems.
I would like to propose that Apple consider creating a real-time HealthKit streaming entitlement for verified partners such as automotive manufacturers participating in the CarPlay ecosystem. This entitlement could be limited to specific biometric signals like heart rate, heart-rate variability and stress index, and should function only when the user explicitly opts in. The data could travel one way from the iPhone to the vehicle head unit during an active CarPlay session, remain local and encrypted, and never be stored in the cloud. A latency of around half a second would be ideal. Technically, this could follow an asynchronous delegate model similar to HKLiveWorkoutBuilder or a Combine publisher interface adapted for CarPlay Health sessions.
A capability like this would extend Apple’s health ecosystem beyond the wrist into the driving environment, allowing cars to respond in real time to the physical state of their drivers. It would strengthen Apple’s commitment to both privacy and safety, while supporting automotive partners that focus on human-centered design. Imagine a driver whose heart rate drops below a vigilance threshold: the Apple Watch detects it instantly, CarPlay transmits the signal securely to the ENERGIZING system, and the vehicle gently adjusts lighting and seat vibration to restore alertness.
This kind of integration fits perfectly with Apple’s long-term vision of “Health Everywhere” and would make a measurable contribution to road safety and driver well-being. I would be happy to provide a more detailed use-case document or to collaborate with the Health Technologies and Car Experience teams to outline how this integration could be implemented securely and efficiently.
Topic:
App & System Services
SubTopic:
Health & Fitness
Hi everyone,
I’m building a health app with React Native using Expo Dev Client on a real iPhone. I need to read Apple Health (HealthKit) data, but the authorization sheet never appears—so the app never gets permissions and all queries return nothing.
What I’ve already done
Enabled HealthKit capability for the iOS target.
Added NSHealthShareUsageDescription and NSHealthUpdateUsageDescription to Info.plist.
Using a custom dev build (not Expo Go).
Tested fresh installs (deleted the app), rebooted device, and checked Settings → Privacy & Security → Health/Motion & Fitness.
Tried both packages: react-native-health and @kingstinct/react-native-healthkit. Same behavior: no permission dialog at first use.
Ask
Is there a known reason why the HealthKit permission sheet would not show on modern iOS when called from a React Native bridge (with Expo Dev Client)? Are there any extra entitlements, signing, or config-plugin steps required beyond HealthKit capability + Info.plist?
If you’re successfully fetching Apple Health data from React Native on recent iOS, could you share the exact steps that made the permission sheet appear and data flow (Expo config/plugin used, Xcode capability setup, profile/team settings, build type, bundle ID nuances, any Health app reset steps, etc.)? This would help me and others hitting the same “authorized call but no prompt/no data” issue. Thank you!
WorkoutKit WorkoutScheduler seems broken with the first beta of iOS 18.2.
I have tested using my app from Xcode and the one that is on the App Store (and working properly on other devices), and it's not working with this new beta of iOS.
They appears in WorkoutScheduler.shared.scheduledWorkouts, but not on the watch.
I even tried with other apps that do the same with
Manual add to Apple Watch with SwiftUI workoutPreview work.
Xcode 16.0
iOS 18.2 Beta 1
WatchOS 11.1
Hi,
I have a workout app in the App Store which mirrors workout data between the phone and watch.
Since iOS 26.x I've been having issues and received reports of the mirroring no longer working. Users in iOS 18 have no problems with this functionality.
Bug description: A workout session is started from the phone app and starts mirroring to the watch companion device. The watch starts the workout session and then the mirroring session is disconnected / lost. Sending data to the companion device fails and ending the session on the phone doesn't end the session on the watch...essentially they become completely disconnected.
Please note I am testing this on physical devices...not simulators.
As a sanity check I've also tried the "Building a multidevice workout app" sample code and it has the same problem.
To re-create on the sample app, I start a workout from the phone, the watch workout starts and then the mirroring session seems to disconnect and is unable to send data.
This is the log from the "Building a multidevice workout app" sample code.
Successfully started workout
Type: Notice | Timestamp: 2025-10-17 06:57:07.341401+02:00 | Process: MirroringWorkoutsSample Watch App | Library: MirroringWorkoutsSample Watch App.debug.dylib | Subsystem: com.example.apple-samplecode.MirroringWorkoutsSampleABC123.watchkitapp | Category: MirroringWorkoutsSampleForWatch | TID: 0x1b2ca7
-[SPRemoteInterface _appRecoverAnyExtendedRuntimeSession:]_block_invoke:4350: Got no sessions back from -[CSLSSessionService existingRunningSessions:] or -[CSLSSessionService existingScheduledSessions:] after receiving a PUICInitializeSessionServiceAction
Type: Error | Timestamp: 2025-10-17 06:57:07.641571+02:00 | Process: MirroringWorkoutsSample Watch App | Library: WatchKit | Subsystem: com.apple.watchkit | Category: default | TID: 0x1b2ca7
Session state changed from 1 to 2
Type: Notice | Timestamp: 2025-10-17 06:57:07.647883+02:00 | Process: MirroringWorkoutsSample Watch App | Library: MirroringWorkoutsSample Watch App.debug.dylib | Subsystem: com.example.apple-samplecode.MirroringWorkoutsSampleABC123.watchkitapp | Category: MirroringWorkoutsSampleForWatch | TID: 0x1b2e87
Failed to send data: Error Domain=com.apple.healthkit Code=100 "Failed to send data to remote session." UserInfo={NSLocalizedDescription=Failed to send data to remote session.}
Type: Notice | Timestamp: 2025-10-17 06:57:07.669922+02:00 | Process: MirroringWorkoutsSample Watch App | Library: MirroringWorkoutsSample Watch App.debug.dylib | Subsystem: com.example.apple-samplecode.MirroringWorkoutsSampleABC123.watchkitapp | Category: MirroringWorkoutsSampleForWatch | TID: 0x1b2ca7
Would appreciate any help with this problem as it's affecting customers.
Thank you
I am working on a cycling fitness app and I want to read the cycling power recorded using my Garmin edge from the Garmin Connect App. Currently the data is not transferred to the Health/Fitness Apps. Ideally it would be good to be able to query the power samples similar to the heart rate samples, but even the average power would suffice, as I could then calculate the Kilojoules.