Rengar E Bug

When Rengar is in a bush and with 4 stacks of ferocity, if he jumps (by using his passive or ultimate) and uses his bola (E) while mid-jump to get the entire 5 stacks of ferocity, the ability (E) should reset the cooldown so you are able to use it once more with the now full ferocity stacks and its added effect; however, the ability (E) goes on cooldown while having the full ferocity stacks and you are unable to use the Bola once more in a quick succession to root your opponent. Please fix this as quick as possible!