Wardens Law drop

I don’t have wardens law unlocked in collections yet and realized it’s the weekly nightfall weapon. Idk if my rng is that bad or if i need to unlock wardens law through another method but I’ve ran the weekly nightfall on expert mode 2005 light level (common chance drop for wardens law) about 6 times with no luck and the normal light level 1995 ( uncommon chance drop) about 20 times. Am I just unlucky or am I missing something.(When trying to focus decode from zavala, wardens law is “unlock this item in collections to purchase”)