@Riot Puzzle Lovers: major Fiora W cooldown bug

[Gameplay]

Tried AP Fiora in a Coop game and notice that her W cooldown is often pretty incorrect. Then tried myself and succeeded at recreating it in a Custom game.

I started with: Scaling CDR Quints (15% at 18), 5% from masteries (other info: Project skin) The cooldown was: 18/16/15/14/13 depending on skill level

• regardless of CDR (already weird that it skips the 17, hm?)

When I bought 10% CDR with it fell to 11. Then nothing changed when I bought . The combination of both into lowered the CD to 9 for a minute, before going back up to 11. After reaching Level 15 (and thus 37% CDR), it suddenly dropped down to 9 again.

Now another mystery: When I played AD Fiora after that (Teambuilder), with only the 5% from masteries, the CD was 18/16/15/14/13 again. Building and then decreased the CD to 13 seconds i believe to remember (when the skill wasn't maxed yet).

NOTE HOW THE NUMBER NEVER REACHED AN UNEVEN VALUE! Always full seconds.

EDIT: After checking the supposed Cooldown times, I concluded that her W isn't able to have uneven times for the cooldown. Maybe someone used an "int" instead of a "float" there?

Riddle me this, Riot :)