[b]Context[/b]: the triumph description is ~ "Rapidly defeat opponents with weapons matching the archetype of the current Seasonal weapon". [b]How to reproduce[/b]: the current Seasonal weapon is an Aggressive Burst Pulse Rifle, but you won't see any progress if you try, for example, with Insidious. However, if you try with an Adaptive Frame Heavy Grenade Launcher, like Cry Mutiny, the triumph progresses. It seems that that triumph is using the weapon archetype of the last season. I have not checked if other similar triumph are affected.