I had just completed 4.2 (Jorgenfist), had selected card slot upgrades for my characters and set new decks, leaving 10 cards in the stash. One character (Valeros) was missing a blessing, since I had upgraded his blessing count and had not acquired any during the adventure. The game sent me to the collection tab, where I saw (to my surprise) that I could select blessings for specific deities and not just Blessing of the Gods. Lacking Blessings of Sarenrae for Kyra, I immediately selected all that I could and tried to select the Stash tab to swap some other cards around. I realized that all other options were greyed out and clicked on the collection tab again, and put the extra blessings back. When I went back into my card list, my stash was empty. Restarting the game did not solve the issue.
I am playing on Steam (Windows 7).
PFID: C78600C3667BB269
My party is Valeros, Kyra, Merisiel and Ezren.