Warlord's Blood lust bug or new mechanic?

ive noticed recently in my games that when using warlords blood lust, the only time you lifesteal is when you have an energized attack, even if you buy lifesteal, last game as draven i had bloodthirster and mercurial scimitar, the only time i ever lifestealed, was when i had an energized attack, normal auto wasnt proc'ing lifesteal at all.

so basically warlords bloodlust is cancelling your ability to lifesteal and the only time u can lifesteal is when you have an energized attack.