WWW isDone when lost internet connection, it return true and not wait for internet connection (Andriod)

Sorry if my english is not well, I try to download asset bundles from www and check if download is done and error is null then write file into local disk. This is my code.

IEnumerator DownloadAssetBundle(){
 for (int i = 0; i < firstJson.total; i++) {
    WWW fur = new WWW(firstJson.data*.assetBundleAndroid);*

yield return fur;
Debug.LogError("WWW is done = " + fur.isDone + " & WWW error is " + fur.error);
if (fur.isDone && string.IsNullOrEmpty(fur.error)) {
System.IO.File.WriteAllBytes(path + “/” + firstJson.data*.sku + “.unity3d”, fur.bytes);*
On Editor everything work fine, when i turn off internet yield return is wait for internet connect to continue download but on andriod yield return is not wait for internet it return “WWW is done = true & WWW error is cannot resolve destination host”.
How can i make andriod work like editor? Thank you

It works as expected (on desktop the network timeout is probably higher than mobile), in real apps you really don’t want to wait forever and instead you should catch the error and eventually notify the user.