PHAsset, PHImageManager requestAVAssetForVideo not downloading full size video from iCloud

Hello,

I am using the below code to request for video to be downloaded from iCloud. But the downloaded video size does not match with the original size of video.

            PHVideoRequestOptions *options = [[PHVideoRequestOptions alloc] init];
            options.version = PHVideoRequestOptionsVersionOriginal;
            options.deliveryMode = PHVideoRequestOptionsDeliveryModeHighQualityFormat;
            [options setNetworkAccessAllowed:YES];
            [[PHImageManager defaultManager] requestAVAssetForVideo:asset options:options resultHandler:
             ^(AVAsset *avAsset, AVAudioMix *audioMix, NSDictionary *info) {

}

Original size of video, getting it from below code

NSArray *resources = [PHAssetResource assetResourcesForAsset:asset];

for (PHAssetResource *resource in resources) {
        if ((resource.type == PHAssetResourceTypeVideo) || (resource.type== PHAssetResourceTypePhoto)){
            return resource;
        }
    }

[resource valueForKey:@"fileSize"]

The original Size and the downloaded size of video is not matching. Can anyone help me to debug what is the issue here