AVAudioEngine - Required condition is false: format.sampleRate == hwFormat.sampleRate AudioProcessorEngine.installTap()

func start() {
        do {
            try AVAudioSession.sharedInstance().setCategory(.playAndRecord, mode: .default, options: .mixWithOthers)
        } catch let error {
            print("Error setting audio session category: \(error.localizedDescription)")
        }
       
        do {
            try AVAudioSession.sharedInstance().setActive(true)
        } catch let error {
            print("Activating play and record AVAudioSession failed with error: \(error.localizedDescription)")
        }
       
        self.audioEngine.reset()
        self.audioEngine.prepare()
       
        if !self.audioEngine.isRunning {
            self.installTap()
       
            do {
                try self.audioEngine.start()
            } catch let error {
                print("Error starting engine: \(error.localizedDescription)")
                if isCalibrationConfig {
                    AnalyticsFunctions.reportErrorRecordingFailed()
                }
            }
        }
    }

func installTap() {
        print("Engine started and tap is installed")
        let mic = self.audioEngine.inputNode
        let micFormat = mic.inputFormat(forBus: 0)
   
       
 
        if !isMicTapInstalled {
            mic.installTap(onBus: 0, bufferSize: 2048, format: micFormat) { (buffer, time) in
                if let delegate = self.delegate {
                    if self.isAnalysisConfig {
                        if AVAudioSession.sharedInstance().isOtherAudioPlaying || self.calibrationValidation {
                            delegate.pcmTap(pcmBuffer: buffer)
                        }
                    }
                    if self.isCalibrationConfig {
                        delegate.pcmForCalibrationTap(pcmBuffer: buffer)
                    }
                }
            }
            self.isMicTapInstalled = true
        }
    }


func stop() {
        self.removeTap()
        self.audioEngine.stop()
        AudioUnitUninitialize(self.audioEngine.inputNode.audioUnit!)
        self.audioEngine.reset()
        print("Audio engine did stop and removeTap() was called")
    }

This is the code basically start(), installTap() and stop(). Engine is initialized in the Class.

The exception comes in on the new iPhone X and above where on route change starting the engine results in the exception:

Fatal Exception: com.apple.coreaudio.avfaudio
required condition is false: format.sampleRate == hwFormat.sampleRate