[GAMEPLAY] Keybinding

I use a Razer DeathAdder Chroma mouse and bind 2 items on the 2 buttons located on the side of the mouse. Whenever I use active items that I have to cast on someone else like Blade of the Ruined King or Face of the Mountain, it activates my E ability instead of the item especially when I am moving. For example in game while I am playing Vayne and trying to chase someone to kill them, I use the side button of my mouse to use BortRK on the enemy, instead of BotRK activating, condemn activates and pushes them away. After that I try to use it again and it works (maybe because my condemn is on cooldown so it was not triggered?).

1. Play Vayne or Leona
2. Buy BotRK or FotM
3. Use these items on another champ
4. E activates instead of the item (Vayne condemns them away or Leona's Zenith Blade activates)

I played 3 Vayne games and 1 Leona game and the bug appeared in all games.