Fionna and Cake Glitch

Just for the heck of it, and also to make it to the third F&C quest so that I could increase my heart maximum, I played some Fionna and Cake. Note that you can use only Fionna or Cake as your hero, not your regular hero. But because my regular heroes are low-level, this was not an issue for me. (Don't forget, my heroes are low-level so that the Deck Wars match cost is only one heart.)

When I came back to Deck Wars, there was a glitch where it wouldn't let me play my normal heroes. I could only play Fionna or Cake! Which was okay, because they were Level 5 heroes with extra hit points and card slots. But, being level 5 heroes, it cost two hearts to play each match in Deck Wars.

After I quit the game (fully exiting) and restarting, I was able to use my normal heroes, once again. But the pics above prove the glitch.