How to properly sort contacts by date of birth

How to properly sort contacts by date of birth

I want to sort out my contacts by their date of birth - this month. 
When I apply this filter, it gives me zero result because it sorts our according to real time and real year -- for example if I apply "this month" filter January 2020, then it only gives me contacts who born in January 2020, which is none.......

How can I solve this problem and sort properly?