[Client] Champion Mastery Tokens

At the end of the game in the statistics screen, when I have achieved and S- or higher rank on a champion and gained mastery level 5 in the same game two pop ups appear, one saying you have achieved mastery level 5 and another saying you have earned a token towards champion mastery level 6 due to the S- or higher rank. However when I then go to the loot and crafting inventory these tokens do not appear.

The way to get this bug is:

1. Have a champion that is mastery level 4 and only one game off mastery level 5
2. Play a game as this champion earning and S- rank or higher in that game and achieving mastery level 5.
3. Two pop ups appear as explained above
4. The token is not in the loot and crafting inventory.

This has only happened twice to me, once on Azir today where i got mastery level 5 and a rank of S+ and once a few weeks ago on a champion I can't remember exactly but I think it was Vi.

Many Thanks Slashmer