I just played a set of Practice Pandora games and repeatedly had haste fail to work. It happened for multiple cards, including at least Angry Yak Attack, ScourgeFlame Spector, and Wind Soldier. It was quite frustrating, occurring in 3 separate games.
The Spells appeared to work as normal apart from haste. Wind soldier would just summon then die. Yak attack summoned 3 Yaks but they were unable to move or attack, causing them to die horribly on opponents turn. I managed to win one game but the bug cost me both losses and was particularly frustrating in my last game when I would have pulled out the win on the last turn, after already having Yak Attack fail, but my ScourgeFlame just sat there next to opponent’s orb, mocking me as I died on opponent’s turn.