[GAMEPLAY] Attack speed drop on Rek'Sai

When i reached late game, my champion's (Rek'Sai) base attack speed dropped to ~0.4, bringing it to 1.02 with the effects of my ulti's passive and trinity force. I joined de history. I couldn't trade with opponents, could farm efficiently my passive for sustain, and have been useless for the last 15 minuts of the game, bringing my team slowly to a loss.

I don't know when the drop occured. What i ask is :

1. Please find why this happened, and find a way to fix it, Rek'Sai being one of my favorite champs, i really don't like having to let her go if she's open, just because of the thought of seeing this bug occur once again.
2. Please cancel that loss for me and my team, because it was a ranked game, and this feels pretty awful.

I hope Riot moderators will do something, please...