Randomizing Drag and Drop Items - HELP!!! (I'm new to Storyline 360)

First, be sure you need to randomize. Pedgogically, randomizing is useful only if learners are repeatedly taking the quiz, or if they might be in a position to share answers with each other. Otherwise, for each distinct person, the cards are essentially in a random (unpredictable) order.

The Shuffle Answers option only effects items that are on the base layer. Of course, if you take the items off the layers, and put them in a stack on the base, then reveal items one at a time and shuffle items options will function as intended.