Sleep Talk not hitting dark types?

Question

My grimmsnarl has :
spirit break
Bulk up
Rest
Sleep talk

When I use sleep talk and get spirit break it has no effect on dark types. (Effects everything else)
Is this a feature in the Pokemon sword or is it something from previous games

Comments

Starting in Generation 7, prankster-boosted moves fail against other dark Pokemon. Does your Grimmsnarl have prankster?

Answer 1

Prankster moves (including sleep talk attacks) have no effect on dark types (since gen 7). its more then likely that your grimsnarl has prankster in this instance