need help with lost sector

[dense gale]

Im trying to get Assassins Cowl, and I have every single exotic but it and now im getting items that I already have whilst doing lost sectors how

[teal moss]

you need to complete the shadowkeep campaign on your hunter first.

that, stormdancer's brace, and phoenix cradle, one for each class are all locked behind that completion before they can be obtained other places.