Sacrificing Verrak, Warped Sengir to an ability that also costs life to activate triggers Verrack when it shouldn't.

[Tharkon]

When [[Verrak, Warped Sengir]] is sacrificed to [[Razaketh, the Foulblooded]], Verrak's ability triggers.
I don't believe this should happen because the ability is not activated before Verrak is sacrificed and Verrak is not on the battlefield after it is sacrificed. So at no point is Verrak on the battlefield when the ability is activated.

[github-actions]

Verrak, Warped Sengir - (Gatherer) (Scryfall) (EDHREC)

{1}{W}{B}
Legendary Creature — Vampire
2/2
Flying, deathtouch, lifelink
Whenever you activate an ability that isn't a mana ability, if life was paid to activate it, you may pay that much life again. If you do, copy that ability. You may choose new targets for the copy.

Razaketh, the Foulblooded - (Gatherer) (Scryfall) (EDHREC)

{5}{B}{B}{B}
Legendary Creature — Demon
8/8
Flying, trample
Pay 2 life, Sacrifice another creature: Search your library for a card, put that card into your hand, then shuffle.

[alexander-novo]

I can confirm that the way the rules are written, Verrak shouldn't trigger in this situation.

[JayDi85]

Must be fixed, related test: test_MustNotTriggerOnDiscardCost