Collectible Card Game Headquarters

Describe the Bug:
1- I attacked with Xantid Swarm and on AI's turn game went on a thinking loop.
2- The special effect card has an attached empty legacy from text to it(has only title).

Which card did behave improperly ?
Xantid Swarm

Which update are you using?(date,name)Which type(Duel,Gauntlet,Sealed Deck)
Manalink 2016/08/27: Eldritch Moon v2, duel

What exactly should be the correct behavior/interaction ?
1- Xantid Swarm no loop.
2- Attached to special effect legacy has something like "opponent can't cast spells this turn" or rules text.(of course if we now have a way to do these effects without the horrid special effect card even better).
Are any other cards possibly affected by this bug ?
-

I tested Oriss, Samite Guardian and it seems that the problem happens when you activate granduer ability on your own turn.Xantid Swarm can only attack on your own turn so will always demonstrate this bug in contrast to Oriss, Samite Guardian that seems to work fine if granduer ability (clause: Target player can't cast spells this turn)is activated on opponent's turn.