Missing Hextech Box

I played a game with Kha'zix and did really well. When the game ended the score screen wasn't loading so I clicked the skip button. I then went to check my champions page to check if I had gotten an S and I had. I know because it's my first one with him since the crafting system was implemented. The champion picture even has the border around it indicating that a box was received. However, when I went to check the crafting inventory, the box wasn't there. I think there's a bug where if you skip the score screen, it doesn't award you a box. I have yet to try replicating the bug.