I imported the GeoJSON file of the boundaries of the Italian regions. I think everything went well because I saw the regions by opening a map or a table in the CODAP document. The only doubt is that you do not see the small icons of the regions in the Boundary column of the table. (See screenshots that I attach to understand better). Can it depend on whether the GeoJson file has not yet been uploaded to your server or is it a lack in the file itself?