HealthKit - HKWorkoutRouteBuilder never returns from insert when created from newly added iOS HKLiveWorkoutBuilder API on Simulator

Has anyone had success using the HKWorkoutRouteBuilder in conjunction with the new iOS support for HKLiveWorkoutBuilder?

I was running my watchOS code that worked now brought over to iOS and when I call insertRouteData the function never returns. This happens for both the legacy and closure based block patterns.

    private var workoutSession: HKWorkoutSession?
    private var workoutBuilder: HKLiveWorkoutBuilder?

    private var serviceSession: CLServiceSession?
    private var workoutRouteBuilder: HKWorkoutRouteBuilder?

    private func startRouteBuilder() {
        Task { @MainActor in
            self.serviceSession = CLServiceSession(authorization: .whenInUse)
            self.workoutRouteBuilder = self.workoutBuilder?.seriesBuilder(for: .workoutRoute()) as? HKWorkoutRouteBuilder

            self.locationUpdateTask = Task {
                do {
                    for try await update in CLLocationUpdate.liveUpdates(.fitness) {
                        if let location = update.location {
                            self.logger.notice(#function, metadata: [
                                "location": .stringConvertible(location)
                            ])

                            try await self.workoutRouteBuilder?.insertRouteData([location])
                            self.logger.notice("Added location")
                        }
                    }
                } catch {
                    self.logger.error(#function, metadata: [
                        "error": .stringConvertible(error.localizedDescription)
                    ])
                }
            }
        }
    }

I did also try CLLocationManager API with delegate which is what my current watch code uses (a bit old). Same issue.

Here is what I've found so far:

1. If the workout session is not running, and if the builder hasn't started collection yet, inserting route data works just fine
2. I've tried different swift language modes, flipped from main actor to non isolated project settings (Xcode 26)
3. Modified Apple's sample code and added location route building to that and reproduced the error, modified sample attached to feedback

This issue was identified against Xcode 26 beta 2 and iPhone 16 Pro simulator. Works as expected on my iPhone 13 Pro beta 2.

FB18603581 - HealthKit: HKWorkoutRouteBuilder insert call within CLLocationUpdate task never returns