I’m not sure if this is a bug, but I’m leeching with Drain Life while I’ve got the Lay Waste node (cannot leech) in Drain Life.
I’m a Lich, so I’ve got the base +1% leech plus Survival of the Cruel’s +4% leech, I don’t have any chance to proc ailments that would leech, but I do also have 3 points in the Condemnation node for 3 stacks of Damned (25 necrotic damage per sec for 3 secs) which would be 75 necrotic damage per sec * 365% necrotic damage (= ~350 necrotic damage per sec). At 5% leech that would give me 17 health over 3 seconds (per tick presumably) and I’m using Exsanguinous & can leech from 54hp up to 354 in ~5 seconds which is roughly 60 life/sec (ignoring the degen from the chest).
TLDR - Is Lay Waste disabling leech for the skill, or is it just applying a flat -30% leech modifier (to get back to 0% leech assuming you have no other sources of leech) which can then be worked round if you have any external sources of leech (so +30% leech - 30% + 5% = 5% net leech).
Edit: and I’m not using any other skills.