Trying to count unique URL's for overdue sites based on max scan date for that month

Trying to count unique URL's for a given month that have "overdue" in the overdue status field. Has to be broken out by month and I want the overdue status to be from the line that has the max scan date for that particular URL for that particular month. Some URL's are scanned multiple times and the first scan date might say "overdue" but the next will be blank which means it would not be in the count. Also, will break out by Region and Sector.

I tried using a calculated max scan date for given month in formula but not sure that formula is even right { FIXED [#URL]: MAX([Scan Start Date])}

Then I try to count the # of sites overdue:

{ FIXED [#URL], [max scan date for given month]: COUNTD(IF [Overdue Status]= "overdue" then [#URL] end)}

Right now the count includes all Overdue for that month, not just from most recent scan.

I am not the best at formulas and it has been awhile since I have worked on anything like this. I have spent hours trying different formulas but need help.. thanks to whoever can help. It will be appreciated!!