Today, when I logged on, I hadn't gone to the Oracle yet. However, clicking on the Arena made the tutorial screen appear for me with a Skeleton card and also set all my Electrum back to zero (fortunately I didn't have much stored on it.). Refreshing the page and reloading the game still gave me the Arena Tutorial when I didn't spin the Oracle. After I did spin the Oracle, however, my deck and electrum weren't recovered - just a blank slate and my current Oracle card (Phase Shield).
Screenshots:
