✅ Value doubles when assigned to a variable

public IDeckStorage BuildDeckStorage(
        ISet<ICardStorage> main,
        ISet<ICardStorage> discard, ISet<ICardStorage> active
    ) {
        
        DeckStorage output =  new DeckStorage {
            Main = main,
            Discard = discard,
            Active = active
        };
        return output;
    }