Background transfer of HLS using makeAssetDownloadTask only downloads about half of the data

I am using AVAssetDownloadURLSession's makeAssetDownloadTask method on iOS 15 to simultaneously play and download an HLS VOD stream. Sample code:

@objc func createDownloadSession() {
    // Create new background session configuration.
    let configuration = URLSessionConfiguration.background(withIdentifier: "TestAppSession")
    configuration.timeoutIntervalForResource = 60 * 60 * 2
    
    // Create a new AVAssetDownloadURLSession with background configuration, delegate, and queue
    downloadSession = AVAssetDownloadURLSession(configuration: configuration,
                                                assetDownloadDelegate: self,
                                                delegateQueue: OperationQueue.main)
}

@objc func downloadAndCreatePlayerItem(_ url: URL) -> AVPlayerItem? {
    // Create new AVAssetDownloadTask for the desired asset
    let asset = AVURLAsset(url: url)

    // Create the task to download the track.
    let downloadTask = downloadSession.makeAssetDownloadTask(asset: asset,
                                                         assetTitle: "Test Title",
                                                         assetArtworkData: nil,
                                                         options: nil)

    // Start task
    downloadTask!.resume()

    // Return the URL asset
    return AVPlayerItem(asset: downloadTask!.urlAsset)
}

Everything seems to work fine; it starts pulling the data down at a fast rate, and plays the audio immediately.

However, after a few seconds it stops downloading. It seems to only load around 15 minutes of the HLS audio (I can see the loadedTimeRanges).

How do I get it to download the entire HLS stream? Is there some throttling I am encountering by the OS? The app is in the foreground, though it is a background session. Anything I'm missing? Thank you in advance!