Celebrations Mew- Mysterious Tail Ability

Mew's ability glitches and will not let you take items from its ability. I went to select Battle VIP Pass from Mew's ability and the game would not let me. This is getting kinda frustrating, since I can't test paper every day I like playing online against others and trying out my decks. However, Gardevoir, the deck I planned to bring to NAIC, is constantly getting hit with effects like this and making practicing next to impossible.