Rocket Girl Tristana bug

I was playing Tristana with the rocket girl skin (along with the chromapack, the red haired one) and I noticed that the effects (i.e rockets instead of canonballs) were not as they should be. Instead they were the default Tristana effects.

I'm not sure why this happened, I do know that every time I play Tristana the set skin is Classic even though on every other champion it's the last skin I used. I haven't played a game since then but it was an issue.