Apparently, there was some kind of bug playing Gwent against the first guy you meet in White Orchard, the historian in the inn where you first go with Vesemir. Every time I passed, the the game crashed (PS4 disc copy) so I skipped that and tried to played again Gwent later in the game when I went to Velen. I since went back to white orchard hoping to challenge that guy again but I failed to find him again.
Is there a way to play against him somewhere else? If you beat him, does he give away a card?