Leaderboard doesn't show in my game

Hi, I'm having problems with the Leaderboard.
I made a button to press with Platform-Show Leaderboard. I also registered the ID to IOS and gamecircle.
But I checked it out in IOS beta test, the Leaderboard screen doesn't shows up, my app also got rejected because the Leaderboard didn't show up. is this GS error or did I do something wrong?
I checked in Amazon and Google play it's working very fine.