RANKX not working properly (Adding 1 to the Rank when filtering a selection)

[Wycliff94]

Hi 

I have a retail dashboard, where I analyse sales performance by band. I have 3 formulas that rank all Brands by the store (based on the type of product sold).

- Niche Rank (Ranks all sales from 'Niche' products)

RANK(NICHE) = IF (
    NOT ( ISBLANK ( [NicheSales(TY)] ) ),
    RANKX (
        FILTER ( ALL ( 'Niche Dashboard'[FINAL BRAND]), NOT ( ISBLANK ( [NicheSales(TY)] ) ) ),
        [NicheSales(TY)]
    )
)

- Classic Rank (Ranks all sales from 'Classic' products)

RANK(CLASSIC) = RANKX(ALL('Niche Dashboard'[FINAL BRAND]),[ClassicSales(TY)])

- Overall rank (Ranks total sales)

RANK(OVERALL) = RANKX(ALL('Niche Dashboard'[FINAL BRAND]),[NDAllSales(TY)])

However, I noticed that when all brands are selected, the RANKX fuctions works perfectly, but if I select just 1 brand (see the second picture) the ranks go up by 1 for the selected brand. I have no idea what the issue is.

UNFILTERED

FILTERED