Since I began playing the game, Left Alt has been my preferred key for melee and F has been my preferred key for parry. It no longer works, from what I've gathered, its specific to the action you would like to preform. It no longer works for any ability buttons as well as parry if you swap it to left ALT. Voice chat works if bound to Left Alt. Not sure why this is happening but each bind has a different reaction to being bound to Left Alt