Unity: Apple Game Center iOS7 registers the scores

My game is made using Unity 4.5 and the UnityEngine.SocialPlatforms.GameCenter.

My game is in the app store. If I play the game and beat my high score, it is reported in Game Center and I see myself in the leaderboard. If I play with another device, it registers the score as well and I can see the 2 scores and the 2 players. Everything looks fine.

BUT, and this is my problem, if I relaunch the app on the 2 devices 30 minutes after, the scores have disappeared from the leaderboard in game center. (And if I check directly on the iTunesConnect website, my leaderboard is empty too).

I'm having hard time to solve this problem considering that in Sandbox mode it works pretty well, my high scores being here for weeks now.

Thanks if you can help.

PS: My leaderboard in Game Center as the following parameters: score format type: integer, score submission type: best score, sort order: high to low, score range: 0 to 10000. When I report the score in Unity C#, my leaderboard ID (string) and my score (long) are correct.

I use the function

void ReportScore (long scoreGC, string leaderboardID) {
    Social.ReportScore (scoreGC, leaderboardID, success => {
        Debug.Log(success ? "Reported score to leaderboard successfully ("+scoreGC+")" : "Failed to report score");
    });
}

When I debug, it's a success. So the score should have been sent to game center. When I check game center on my device, the score is displayed. But 30 min later, it is not anymore. I guess it has been only saved on the local cache but not online. Is it a problem with the Social library of Unity or with Apple Game Center iOS7?

Some one from Apple posted

Indeed we did find a problem! We are working on a fix for this issue. Once this is resolved the scores for your leaderboards will start processing. We do not have an ETA yet but will keep you posted. Thanks for your posts :)

on Apple's developer forums on this thread: https://devforums.apple.com/message/1028533#1028533