I activated the ultimate ability on the royal scions to draw 4 and deal damage. Opponent countered the damage ability with siren stormtamer. This left me with 10 cards in hand but upon reaching discard, I couldn't select 3 because the cards kept bouncing back and forth when clicked on (playing on Android). When I finally clicked at the perfect time, apparently, it highlighted the card to select it for discard. I proceeded to do this but upon reaching 3 highlights, the submit button stayed greyed out and didn't let me click to discard. Eventually I highlighted the entire hand but by then I lost due to time out. This was in historic brawl BTW with Nicol bolas the ravager at the helm.