Getting less double exp games than I entered.

I’ve on a few occasions enter various different amounts of double exp. The first time I entered 12 games I noticed it seemed short. Then in two other instances I entered 6 and got 5. I wasn’t 100% sure though, but this last time I entered 15 and after my first game it said 13 remaining. I tracked all my theatre videos and after 14 games I was out of double exp, even though I entered 15. Anyone encounter this? I know it’s only one game, but it’s happened a few different instances now and I have more codes to put in :frowning: