The Elder Scrolls V: Skyrim

The Elder Scrolls V: Skyrim

Sacrosanct - Vampires of Skyrim
Dracodard_93 Jun 9, 2020 @ 12:32pm
Sacrosanct mod : Borrowed Time mechanic.
Borrowed Time: (Master) Deals 5 magic damage for 20 seconds to the living or undead. When time runs out, deals damage equal to all Health lost by the target during this time.

So, i cast it on enemy and i cast dot on them too, but when the spell (BT) is over, his final effect don't proc.

Is there a special mechanic ? Or it's bug ?