Im having the same trouble. Not in nightfall because i am not a fan of the cloaks, but to each their own. But i ran heroic strikes for maybe a little over 2 hours last night because i want to collect the rest of the strike soecific gear and got almost nothing. Maybe one treads upon stars. I wonder if they tweaked the drop rates after people farmed omnigul for grasp of malok. I know i finished that week with 6+ grasps and bonds each. I was getting a strike legendary on every other kill for her.