Dax Comparing Two Columns From Different Tables Returning Incorrect Result

Anonymous 
Is this what you're looking for?

Count of Missing Barcodes = 
COUNTROWS ( 
    EXCEPT ( 
        VALUES ( 'DistProfile v1-3'[Barcode] ),
        CALCULATETABLE ( 
            VALUES ( 'DASHBOARD_RESULTS_HIST (2)'[BARCODE] ), 
            ALLEXCEPT ( AcceptanceCalendar, AcceptanceCalendar[Year] ) 
        )
    )
)