AudioKit - audio engine configuration changes periodically - ios

Question

I have an app that uses samplers to play loops. I am in the process of converting my app from using AVAudioEngine to AudioKit. My app now works well except for this: Approximately every 1-3 minutes, my app receives two .AVAudioEngineConfigurationChange notifications in a row. There is no apparent pattern to its repetition and this happens on both my iPhone 6s and new iPad.
Here is my init code for my "conductor" singleton:
init() {
//sampler array
//sampler array is cycled through as user changes sounds
samplerArray = [sampler0, sampler1, sampler2, sampler3]
//start by loading samplers with default preset
for sampler in samplerArray {
//get the sampler preset
let presetPath = Bundle.main.path(forResource: currentSound, ofType: "aupreset")
let presetURL = NSURL.fileURL(withPath: presetPath!)
do {
try sampler.samplerUnit.loadPreset(at: presetURL)
print("rrob: loaded sample")
} catch {
print("rrob: failed to load sample")
}
}
//signal chain
samplerMixer = AKMixer(samplerArray)
filter = AKMoogLadder(samplerMixer)
reverb = AKCostelloReverb(filter)
reverbMixer = AKDryWetMixer(filter, reverb, balance: 0.3)
outputMixer = AKMixer(reverbMixer)
AudioKit.output = outputMixer
//AKSettings.enableRouteChangeHandling = false
AKSettings.playbackWhileMuted = true
do {
try AKSettings.setSession(category: AKSettings.SessionCategory.playback, with: AVAudioSessionCategoryOptions.mixWithOthers)
} catch {
print("rrob: failed to set audio session")
}
//AudioBus recommended buffer length
AKSettings.bufferLength = .medium
AudioKit.start()
print("rrob: did init autoEngine")
}
Any AudioKit experts have ideas for where I can start troubleshooting? Happy to provide more info. Thanks.