Drop key suddenly not allowing me to switch between tarot cards w/starter deck?

Sorry for bothering y'all for such a simple problem, but this hasn't happened to me previously and I can't find much about it anywhere else.The drop key is bound to default (LCtrl), and dropping items works fine. When I hold it down, my trinkets and cards drop. However, I noticed today that I'm no longer able to select which card I want to use from my starter deck by pressing the drop key once. I've tried binding it to another key, but nothing has worked so far. Has anybody else experienced this? Is there a fix? Thanks!