Stuck on one last Gwent card?

So I'm trying to get the achievement for getting all gwent cards in the base game, and I'm struggling.

I ran around Skellige collecting as many cards as possible and the Miraculous Guide to Gwent book now says I have 0 cards to get from non-important characters but 1 card left on Skellige, nowhere else.

I cannot find this card for the life of me. I've completed the Gwent side quests with Crach and Gremist and all of that, I looted the Nekker off of Hammond, I genuinely don't understand why it's still on one.

I was using the Gwent card tracker that shows all available cards to get on Skellige and I have them all.

I'm a bit stumped :/

Edit: Thanks for your help guys, turns out I was missing the Thaler card from the innkeep at Arinbjorn. Got the trophy and the quest :)