2 things ;-
1) the RL has to be close to the chest for people to loot , a bit strange bit there you go.
2) If you are using Master Loot method then some chests, Pylons is one of them can only be looted by the RL, the solution is to pass the ops leader tag around the raid and let people loot while they are flagged as ops leader. funny bug, but it works.
3) if you are using master loot then the mobs dont drop Biometric Alloys, you have to be on NBG for them to drop