Sylveon ex Angelite attack glitch

Just a glitch I've noticed regarding the attack in the title…

On multiple occasions now, after using the mentioned attack (shuffle two of your opponent's benched Pokémon and all cards attached to them into their deck), I select the two Pokémon, and only one of them is shuffled into the deck, with the other remaining in play.

This just happened with a Charmander remaining in play - it had no Ability or Tool cards attached preventing the attack, nor were there any other Pokémon in play that should have protected it from the attack.

This doesn't happen every time I use the attack, but it's still frustrating and I hope the issue is resolved quickly.