I hear the medallion drop sound but there no medallion

Pretty much what the title says. I know it was a bug for multi-player, but somehow it became an issue for single player as well. I hear the medallions drop but most of the time there is no medallion. I have a chain of 12 spymasters level 3. It used to drop enough locks to easily maintain 2 chains. Now, I barely get one drop per temple run. I completely lost my second chain. Is this a shadow nerf?