[GAMEPLAY] Kalista Attack Speed calculated incorrectly

I was recently in a game as Kalista, and noticed my attack speed was incredibly slow, even after buying BOTRK and Runaan's Hurricane. The attack speed value was 1.36, at level 14, with the two aforementioned items, with my oathsworn support beside me, and with the Fury mastery (I did not have attack speed runes). This seemed off to me, so after the game I immediately hopped onto theorycraftr.com, inserted all the items, levels, etc. and found that my attack speed should have been 1.89. Now, I don't know for sure that theorycraftr's numbers are exactly correct, but something was definitely off about my attack speed in that game,

TL;DR: had a game on Kalista where my attack speed was atrociously slow (1.36), even after two attack speed items. There might be a bug in there.