Hierarchical Ranking Positive to Negative values

Sorry for not posting a sample dataset before. 

Here is a sample data for Locations and Income tables; 
Location Table:

Income table:

both Locations and Income tables joined by Store_Number. 

Here are images for what is expected; 

Expanded matrix: 

Collapsed matrix:

Instead, I'm getting this in Power BI: 

I don't understand why the transition from positive to negative 'Operating Income' generates a blank row in the matrix and assignes it a rank = 2.

Dax used to create the measure 'Op Income Rank': 

Op Income Rank = 
var rank_region =
RANKX(
     ALL('Location'[Region]),
      [Operating Income], , DESC
      )
var rank_store = 
RANKX(
    FILTER(
        ALL('Location'[Store Name], 'Location'[Region]),
         'Location'[Region] = MAX('Location'[Region])
         ), [Operating Income], , DESC
    )
return
    SWITCH(TRUE(),
        ISINSCOPE('Location'[Store Name]), rank_store,
        ISINSCOPE('Location'[Region]), rank_region,
            BLANK() )

Measure 'Operating Income' was previously calculated, it doesn't present any issue. 

I have researched this issue in the web, but no body had this problem before. I may be doing something wrong, but I can not see what is it. 

Thanks in advance!