Queried heart rate samples in the past interval have lower resolution than recent samples

I am querying heart rate samples taken during a workout. For all of the mentioned cases below I'm wearing an Apple Watch and using the stock Workouts.app in the watch.



If I query heart rate samples for a recent workout, it being yesterday or the past month for example, I get the full samples. If I query a workout let's say, two/three months in the past the samples I get back look "choppy" with a lot of missing data. (See attached image)

imgur.com/a/FbMSBoa

How am I getting the heart rate samples?

Code Block swift
extension HKHealthStore: HKHealthStoreCombine {
    public func get<T>(sample: T, start: Date, end: Date, limit: Int = HKObjectQueryNoLimit) -> AnyPublisher<[HKQuantitySample], Error> where T: HKObjectType {
        let subject = PassthroughSubject<[HKQuantitySample], Error>()        
        let sampleType = HKSampleType.quantityType(forIdentifier: HKQuantityTypeIdentifier(rawValue: sample.identifier))!
        let predicate = HKQuery.predicateForSamples(withStart: start, end: end)
        
        let query = HKSampleQuery(sampleType: sampleType, predicate: predicate, limit: limit, sortDescriptors: nil, resultsHandler: { (query, samples, error) in
            guard error == nil else {
                logger.error("Error fetching samples of type \(sample.description) from \(start) to \(end) with a limit of \(limit): \(error!.localizedDescription)")
                subject.send(completion: .failure(error!))
                return
            }
            let samples = samples as? [HKQuantitySample] ?? []
            logger.log("Successfully fetched \(samples.count) samples of type \(sample.description) from \(start) to \(end) with a limit of \(limit)")
            subject.send(samples)
            subject.send(completion: .finished)
        })
        self.execute(query)
        return subject.eraseToAnyPublisher()
    }
}

Code Block swift
healthStore.get(sample: HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.heartRate)!, start: workout.startDate, end: workout.endDate)
            .map({
                $0.compactMap({ $0.quantity.doubleValue(for: UserUnits.shared().heartCountUnits) })
            })
            .replaceError(with: [])
            .receive(on: DispatchQueue.main)
            .sink(receiveValue: {
                self.heartRate = $0
            })
            .store(in: &bag)

Is this some kind of wrong way that I am working with HealthKit? I don't know what the issue can be but it looks like accessing heart samples in the "past" are somewhat archived and I don't get the full resolution.