Game Center Authentication callback returns false

Hi, I am seeing a problem with Game Center authentication where if I start the game from XCode and sign in to Game Center then Social API returns true in the callback but if I disconnect from XCode and run from the device by clicking on game's icon the Social API callback returns false, although the sign in is successful [I can see Welcome Back .... notification]. Did someone else also see this problem? Is there anything different when running from XCode vs clicking on device icon? PS: Same code works correctly for Google Play