(GAMEPLAY) Cho'Gath Feast Cooldown

Whenever you use feast on a minion/monster, doesn't seem to matter the cooldown for me was show 25 sec on the button in game and the cd reset on that amount of time. With 35% cdr his feast cd was showing 52 sec but the cd timer on the button was showing 25 sec everytime, and it reset in 25 sec as well.