I just ran the daily heroic story, Sword of Crota, on lvl 30. Juggler modifier is active to prevent ammo drops for whichever weapon is currently equipped. The problem I found only pertains to the gameplay that occured before I picked up the sword. I only used my primary and the enemies were droping primary ammo like normal. Yes, even in the area where the sword is. It was as if the juggler modifier wasn't working. I've noticed this since the 1.1.1 update.