Not sure if it's a bug or not...
I had connection issues after entering the oracle, which forced me to turn off and back on my router. I then got back in the menu and received the "disconnected" message. I refreshed the page, but the oracle button has been in gray since then, like I already did the spin (which isn't true). I entered the arena section and found basilisk blood as oracle card, it's like the game did the spin for me.