DAX ISBLANK Test and Returning Date Value

First time poster - apologies if any noob mistakes in this post:

Relatively new to DAX and encountering the following challenge. The logical test seems to be working fine but when a date value is returned it is not in date format. Am I simply missing a formatting function when the test=FALSE and an available date value should be returned?

Result from native date field in data. Not a measure. Using ‘latest’ in field specification on Card object.

Result from measure created to make available with ISBLANK function.
m_Max_Task1_Mail_Date = MAX(TABLE[Task1_MailDate])

Result of measure below if ISBLANK test is true - Works as expected
_NoBlank_Max Task 1 Mail Date = IF(ISBLANK([m_Max_Task1_Mail_Date])," 999 ",[m_Max_Task1_Mail_Date])

Result if ISBLANK test is false - Does not work as expect. Should return m_Max_Task1_Mail_Date
_NoBlank_Max Task 1 Mail Date = if(ISBLANK([m_Max_Task1_Mail_Date]),“999”,[m_Max_Task1_Mail_Date])

It is actually working as expected, in an empty filter context you are getting the max date of the whole table, if filter are active over the table then you are getting max date in that filter context for the currently visible rows, you need to modify the filter context somehow so that MAX returns BLANK. refer to the below screenshots to see how I modify the filter context using CALCULATE, in the case where it returns blank I am checking for the max date of a year(2002) that doesn’t even exist in my date table
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Hi @wrandyrice, did the response provided by @AntrikshSharma help you solve your query? If not, how far did you get and what kind of help you need further? If yes, kindly mark the thread as solved. Thanks!