Collectible Card Game Headquarters

Unless I'm misunderstanding something, the opponent shouldn't have been able to put two Leyline of Singularity in play from its starting hand, as one of the two leylines should have been put in the graveyard.

Edit: the legend rule doesn't seem to be enforced at all. I've been able to play two or more copies of nonland permanents without any issue during the game.

Screenshot and savegame attached.

Thanks.

I confirm the bug both in release and in dev.