I think this is something new - during the action phase after revealing a card, I decide to not go with that card and try and reverse the selection with the big red X. However the card does not return to my hand, but ends up discarded (and remains as a ghost image in the play area). Something similar also occurs during combat resolution - I will select a piece or armor or perhaps an item, change my mind and reverse it, again with the big red x, but in this case the amount of original damage jumps up - last time I experienced this the damage increased from 2 to 6 points. (iOS version, iPad Pro, both up to date, as is the Pathfinder App, as of today's date).