[Not a Bug] Cospri's Malice Failing to Leech

Even with Vinktar, i'm not able to leech on bosses with Cospri Malice, i'll try with Atziri flask.

Edit : I tried on Uber Izaro. Even with Atziri flask, no more leech and my base leech (Leech life gem + warlord mark) doesn't seem to work as it should.

Izaro is really slow, i got time to leech between 2 hits. On the fights, i got no leech from my gem, my curse or my flasks (ony tried Atziri & Vinktar). I'm on std, no essence here, nothing, he almost killed me past run with two slow hits, i wasn't leeching anything.