The DLC1WerewolfFeedPointsScript script attached to the PlayerWerewolfVictimEffect magic effect runs when it shouldn't. I believe this is because the Werewolf Feed effect archetype doesn't have proper support for Papyrus scripts. Taking a look at the WerewolfFeedEffect class in IDA, you can see that it doesn't inherit from the ScriptEffect class, so this isn't too surprising. Admittedly I haven't looked at either of the classes much further than that.
You can see the bug being discussed here:
NexusMods
StackExchange
Reddit
It is simple to reproduce the bug if you know how. Fast travel to
The Ritual Stone and kill the necromancer with the "kill" console command. Transform into a werewolf and then feed on the necromancer. The "Heart consumed, werewolf perk progress increased" notification will be displayed. Wait a couple of in-game hours until your transformation ends. Set your SpeedMult actor value to 1 using the "player.setav speedmult 1" console command, and then fast travel to the other side of the map and then back to The Ritual Stone. When you return enough time will have passed that the necromancer will have respawned. Hit the necromancer with any spell (for example
Soul Trap or
Firebolt) and the "Heart consumed, werewolf perk progress increased" notification will be displayed again when it shouldn't.
To fix this bug I added the DLC1WerewolfFeedPointsScript script to a new magic effect with a Script effect archetype and filled the properties. I then removed the DLC1WerewolfFeedPointsScript script from the PlayerWerewolfVictimEffect magic effect and added this new magic effect to the PlayerWerewolfFeedVictimSpell spell, which is the only spell in the game to use the PlayerWerewolfVictimEffect magic effect. I have attached this fix to this issue for you to reference.
This fix has worked for myself and LordMala as you can see
here, who reported this bug to me. This fix will also have to be adopted by werewolf overhauls such as Moonlight Tales if they make changes to the DLC1WerewolfFeedPointsScript script, PlayerWerewolfVictimEffect magic effect, or PlayerWerewolfFeedVictimSpell spell.