Card costs don’t become cheaper
No bug here. Please search before posting.
Did you happen to introduce Soul Fragments into your deck? If so, it isn’t a bug. Soul Fragments can negate cards effects…
(Ex. Skull , Stiltstepper)
Point your browser over to the wiki, and read on advanced rules here…
https://hearthstone.fandom.com/wiki/Hearthstone_Wiki
- The cost is only reduced if the Skull was Outcast (leftmost or rightmost in your hand).
- If the Skull draws a card that automatically draws a replacement card, such as a Bomb or Soul Fragment, then the replacement card does not receive the cost reduction, because it wasn’t directly drawn by the Skull.