I just noticed the same thing with mine
Interface List:
https://www.wowinterface.com/portal.php?id=551&a=list
Regular List :
https://www.wowinterface.com/downloa...hor-26904.html
Now in the Regular List I know the trigger is when it hits 5k downloads. But with the Interface List via the portal the lowest one is 800 downloads. So appears to be ignoring the check for download count before adding the star.