Math works... Banding doesn't

Activity Index by Account = 

VAR purchases365 =
CALCULATE (
DATEDIFF ( SELECTEDVALUE('A/C Relationship'[Aircraft Date Purchased]), TODAY (), DAY),
FILTER (
Aircraft,
Aircraft[Aircraft Manufacture Code] = "ABC"
|| Aircraft[Aircraft Manufacture Code] = "123"
),
USERELATIONSHIP ( 'A/C Relationship'[Aircraft ID],Aircraft[Aircraft ID] ),FILTER(Aircraft,Aircraft[Aircraft Classification]="JET"||Aircraft[Aircraft Classification]="TURBO")
) 

//Calculating the index based on a calulated column (Task[Activity Index])
var actInd = IF(purchases365<=365,
    CALCULATE(ROUND(SUMX(CALCULATETABLE(Task,
            GROUPBY(Task,Task[AccountId],Task[Engaged__c],Task[DB_Activity_Type__c],Task[CreatedDate],Task[OwnerId])),
        Task[ActivityIndex])+(4*EXP(-0.0027*DATEDIFF(LASTDATE('A/C Relationship'[Aircraft Date Purchased]),TODAY(),DAY))),2)),
            CALCULATE(ROUND(SUMX(
        CALCULATETABLE(Task,GROUPBY(Task,Task[AccountId],Task[Engaged__c],Task[DB_Activity_Type__c],Task[CreatedDate],Task[OwnerId])),
        Task[ActivityIndex]),2)))

return
//Banding Categorization
CALCULATE (
VALUES ( 'Activity Index Grouping'[Index]),
FILTER (
'Activity Index Grouping',
actInd >= 'Activity Index Grouping'[Min]
&& actInd< 'Activity Index Grouping'[Max]
)
)