Key Fragments not showing up in inventory?

The last couple of days I've noticed that after winning a game or two I will get the notification in the post-game screen that I earned a key fragment. Every time I go check this in my inventory after the game I still have the one key fragment I have had for about the last week. This has happened at least 3 times in the last week and I am getting frustrated because I know for a fact I should be able to open another chest by now