Need Help Fixing Measure - Summing a count

Hi All, 

So i have the following measures:

Current Month - Selects the Cost Center for the Currently Selected Month

Current Month = 
var FileDate = SELECTEDVALUE(Dates[File Name])
return
IF(ISBLANK((CALCULATE(SELECTEDVALUE(Workday[Cost Center - ID]), Workday[File Name] = FileDate))), "Exit", CALCULATE(SELECTEDVALUE(Workday[Cost Center - ID]), Workday[File Name] = FileDate ))

Previous Month Cost Center - Calculated Column that gets the prior months Cost Center for each row 

Previous Month Cost Center = 
VAR __prevDate = 
CALCULATE( 
    MAX( Workday[File Name] ), 
    FILTER( 
        ALLEXCEPT( 'Workday', Workday[Associate ID] ),  
        'Workday'[File Name] < MAX( Workday[File Name] )
    )
)
RETURN
    CALCULATE( MAX( Workday[Cost Center - ID]), ALLEXCEPT( 'Workday', Workday[Associate ID] ), Workday[File Name] = __prevDate )

Transfer Check - Checks if the Prior and Current Months Cost Centers have changed

TransferCheck = IF(AND([Current Month] <> [Prev], AND([Current Month] <> "", [Prev] <> "")), 1, 0)

ExitCheck - Checks to see if a record existed in previous month, but not the current month

ExitCheck = IF([Current Month] = "Exit", 1, 0)

I now want to summarize the ExitCheck flag. I have successfully done this with other measures, such as "TransferCheck" which is the following:

Transfer Count = 
sumx(Values(Workday[Associate ID]),[TransferCheck])

This gives me my desired outputs, showing a count by Business for "Transfers". However, when I apply this exact same logic to "ExitCheck", i only get zeroes. Is there something different i should be doing?

Also, here is my (simple) data model

Thanks!