I've run into this too. I wish it would get fixed (first happened to me when I was down to only K, K-Q), but for me it seems to happen (I think) when I double click a card and pick up the card behind it during the card selected animation. So far makikng sure I click in the middle of the cards has done if for me, though I've also triggered it on the discard pile (which you can just cycle through the deck to fix the problem.