Country users not listed

Hi there,

i am looking at the dashboard and can see the number of users etc but when i click on the listed users by countries it comes out a blank.

may i check what settings should i set on the forms for the users country to be displayed and to track the number of users from each country ?

Attached the screenshot for your reference.

My forms presently have a country field for users to select already at the moment.

thanks !