Jace's Defeat not triggering

stikxs

In the match against Kumena in Bo4T I had Jace's Defeat on the board and my first creature was Kiora's loyalty point octopus pack. On Kumena's turn they cast Perilous Voyage, then my support was destroyed but my octopus was also destroyed.

DBJones

If they had another spell above Perilous Voyage in their hand, that's what would show up in the battle log. When Jace's Defeat cancels a card, it just disappears from your hand (or your opponent's hand in this case). Not sure if that's the case here, but I know it can be difficult to spot the cancelled card.