This matches my personal experience - zero key fragments dropped from vosik and the siege engine this week. Fragments are still dropping from chests as usual. https://www.reddit.com/r/DestinyTheGame/comments/5bv512/anyone_else_getting_zero_siva_key_fragments_on/ No one on my fire team got any SIVA key fragments on any of the boss kills. Though we did get them from opening the 4 exotic chests and Aksis Phase-1. I think Bungie messed up the SIVA key fragments drop rate on their latest hot fix. Update: So it seems that not everyone is getting zero SIVA key fragments from WotM boss kills. A very small portion of players are in fact getting a lot. The SIVA key fragments from the 4 exotic chests and Aksis Phase-1 are guaranteed for everyone. Situation for the large majority of players: Most players are getting zero SIVA key fragments from all three boss kills (Vosik, Siege Machine, and Aksis Phase-2). Though, they are getting SIVA key fragments from the 4 exotic chests and Aksis Phase-1. For a small portion of players: A very small number of players I've talked to say that they've been getting 6x SIVA key fragments from each of the three boss kills in addition to the ones from the 4 exotic chests and Aksis Phase-1. Please confirm bungie is aware of the issue.