Death's Oath self damage + Tainted Pact bug

While checking Death's Oath ideas I noticed that when I have equipped Tainted Pact amulet I do not have benefit of chaos damage over time healing instead while leeching life.

I am using both Caustic Arrow and gloves with 'x of chaos damage leeched as life and those leech effects are still not helping with Death's Oath self damage.
The debuff has even description of "You are taking chaos damage over time"

I saw there are already some old posts about it so bumping this bug. Amulet is rather unplayed it would be nice if it would work correctly.