[Bug?] Arcanine EX in test play

I just started playing today and was testing a deck that I received that have Arcanine EX in it. In test play when I am asked to discard two (2) fire energy from the Arcanine EX. If I select two (2) fire energy cards the game will say I selected too many cards to discard. I can continue and discard these or I can choose to cancel that action and remove only one (1) energy card and the game accept this as a valid action.

Is this intentional in test play or is it a bug?