how to import new CPT listings and link them to places? export file doesnt show

When I export csv file of new added CPT “gd_project”, it doesnt show any linked places.

But in these project listings I linked places from new CPT gd_project to gd_place. But why this relationship is not showed in the csv export file? In the file it shows “location_id” = 0 and “locations” is empty and “link_business” is emtpy as well. (what is “marker_json” by the way?)

Therefore: How can I import a file with projects (CPT gd_project) and link them to the places?

Which csv column should I use and what is the input format? The ID of the places separated by comma?

I think there is an error in this export file of CPT.

Thanks for help!