Newsstand Kit downloading not working on cellular network

Question

I have many Newsstand apps on AppStore. They are all from same source code, 1 source and multi-targets. It was fine until now. Recently I updated the apps and some of them have a problem. When trying to download the issues by tapping the download button, it’s not working on cellular network.

Newsstand downloads is based on a tutorial here. And here is a part of my code:

NKLibrary *nkLib = [NKLibrary sharedLibrary];
NKIssue *nkIssue = [nkLib issueWithName:bookID];

if( !nkIssue ) {
    nkIssue = [nkLib addIssueWithName:bookID date:date];
}

if( nkIssue.status == NKIssueContentStatusNone ) {
    NKAssetDownload *assetDownload = [nkIssue addAssetWithRequest:request];
    assetDownload.userInfo = @{@"bookID": bookID};

    NSURLConnection *connection = [assetDownload downloadWithDelegate:self];
    ...
}
...

After calling downloadWithDelegate: method, there is no response from Newsstand Kit on cellular network.

• If I change the connection to Wifi, it starts downloading.
• if turning off Wifi, then the downloading stops.
• if turning on Wifi again, downloading resumes.
• if turning off Wifi again, then the downloading stops again.

One More thing I can’t understand is that one of those apps are fixed, just by re-building and updating the binary to AppStore.

Any help would be appreciated! :D