Trail of torment not deactivating after last gen pops

Desc: I was in a public match against the Xenomorph who used trail of torment on a generator right before the last generator was finished and the killer was permanently undetectable in end game.

Here's the clip of the game:

Step 1 : Play with or as killer(maybe only Xenomorph) in a public match using trail of torment

Step 2: Activate trail of torment 

Step 3 : Have a survivor finish the last generator while trail of torment is still active on another generator

Step 4: Notice the killer is still undetectable

Character played: the Xenomorph

Perks played: hex: face the darkness, hex: plaything, Scourge hook: pain resonance, trail of torment 

Addons played: emergency helmet, multipurpose hatchet

Map: Torment creek

Frequency of the issue: only saw it once

note: I was not able to recreate this in a custom game, I used only trail of torment on a different killer with a different map so there may be other factors