STBFL is buggy.

Jean_Cobra

The perk completely bugs a lot of killers.

- Deathslinger: When you shoot the obsession, you instantly lose two tokens.

-Trickster: Each kunai thrown at the obsession causes you to lose two tokens.

-Nemesis: a tentacle hit without damaging the obsession causes you to lose two tokens.

- Artist: A crow shot at the obsession without inflicting damage causes him to lose two tokens.

The killers that are not impacted by this change are:

The Skull Merchant: Obsession being hurt ONLY by a drone does not lose tokens

Trapper: If the obsession is caught in a bear trap it will not cause the killer to lose any tokens.

- Plague: Vomiting on the obsession to make it sick and inflict a health segment on it will not cause the killer to lose any tokens.

My advice: 

Bring back the old version, but to prevent severe endgame camp: "When doors are powered or opened, STBFL is disabled.