[FairPlay] timeRangeExpectedToLoad value = 0

Starting the download of an asset the timeRangeExpectedToLoad value of the delegate function works

func urlSession(_ session: URLSession,
                    assetDownloadTask: AVAssetDownloadTask,
                    didLoad timeRange: CMTimeRange,
                    totalTimeRangesLoaded loadedTimeRanges: [NSValue],
                    timeRangeExpectedToLoad: CMTimeRange) {

But turning on and off the flight mode when the Task restarts the download the timeRangeExpectedToLoad = 0

Below a log:

CMTimeRange(start: __C.CMTime(value: 0, timescale: 1, flags: __C.CMTimeFlags(rawValue: 1), epoch: 0), duration: __C.CMTime(value: 0, timescale: 1, flags: __C.CMTimeFlags(rawValue: 1), epoch: 0))

Is that a bug or we are doing something wrong?