I have noticed this for the past couple of days. I have a pally swordsman that i use a lot to do spawns. I use a soul seeker and use whirlwind a lot. Used to be i could keep up with mana using whirlwind in mobs. Now mana leech doesn't seem to be working at all. The other leeches still work fine it is only the mana leech that doesn't seem to be working. I tried a katana with a 40% mana leech being the only mod on a few dragons and the spell never went off once. Would use up all mana then attack dragon just swinging the sword without the mana leech kicking in at all. Anyone else noticed this?