Sacred Fire King Garunix and Legendary Fire King Ponix will not trigger to summon themselves if a fire monster in the hand is destroyed both in the hand as well as the GY in the case of Sacred Garunix.
Bug reproduction steps
Destroy a fire monster in the hand while having Sacred Garunix and/or Ponix in the hand, or add them off of Fire King Island. Neither one will trigger.
your replay code
Screenshot OR error code
Sacred Garunix and Ponix should be able to summon themselves from the hand (or the GY with Sacred Garunix) when a fire monster is destroyed in the hand.
What OS are you using