I had 2 ascendant alloy and needed a third to craft the Osteo Striga catalyst. I re-played the weekly story mission on Hero and not only did not get another, but [u]the two Ascendant Alloy I had in inventory disappeared[/u]. I have logged out and re-logged in but that did not correct the issue (not that I expected it would) This appears to be a bug, and should be investigated. 7-year Destiny veteran, and have never had an issue like this.