AudioKit for iOS: Frequency Discrepancy on Simulator vs Device

I am using AudioKit to monitor frequency for a simple guitar tuner application and am experiencing discrepancies in frequency after updating from AudioKit ~4.2 to 4.4, Xcode 9.x to 10, and iOS 11 to 12. Before the updates, I was achieving correct frequency readings on my device. After updating, I am getting accurate results for a low E1 (82.4 Hz) on the simulator, but false readings on the device (alternates from ~23 to ~47 kHz).

I have tried using another device, but achieve the same results.

My viewDidLoad() setting up AudioKit is relatively simple, and I used the AudioKit playgrounds as a guideline:

override func viewDidLoad() {
    super.viewDidLoad()

    // Enable microphone tracking.
    AKSettings.audioInputEnabled = true
    let mic = AKMicrophone()
    let tracker = AKFrequencyTracker(mic)
    let silence = AKBooster(tracker, gain: 0)
    AudioKit.output = silence
    do {
        try AudioKit.start()
    }
    catch {
        print("AudioKit did not start!")
    }
    mic.start()
    tracker.start()

    // Track input frequency, 100ms intervals
    timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) {
        [weak self] (timer) in
        guard let this = self else { return }

        this.frequencyLabel.text = String(format: "Frequency: %.3f Hz", tracker.frequency)
        this.frequencyLabel.sizeToFit()
    }
}

As a sidenote, I am getting Objective-C console output regarding AudioKit classes being implemented in two places. Would this contribute to the issue?

objc[517]: Class AKRhodesPianoAudioUnit is implemented in both /private/var/containers/Bundle/Application/5A294050-2DB2-45C9-BB0A-3A0DE25E87C6/Tuner.app/Frameworks/AudioKitUI.framework/AudioKitUI (0x1058413f0) and /var/containers/Bundle/Application/5A294050-2DB2-45C9-BB0A-3A0DE25E87C6/Tuner.app/Tuner (0x104e177e8). One of the two will be used. Which one is undefined.

Any ideas? Thanks in advance!