attack speed bug with runnans hurricane and kayle

Hi riot, i was in a game playing mid lane and i had bought a , then a , then bought a . my attack speed was at a base of 1.45 with 0 stacks of after getting more gold and dying i then bought the and my attack speed with 0 stacks only went up to only 1.46! only a 0.01 difference when a offers 25% attack speed and the offers 40% that's a difference of 15% surely 15% attack speed buff would offer more than 0.01 attack speed. i hit the undo button and my attack speed went back to 1.45 after repurchasing the it went back to 1.46. idk if this is an interaction with the new or its just a bug on the hurricane and or Kayle pls fix it or at least explain to me why that is.

P.S. I did record the game VIA skin spotlights if you need the video