If you export the developers from an organization A and try to import them to organization B the target organization is not set during import but the organization of the source.
Workround: The import works if you manually change the value of the property
If you export the developers from an organization A and try to import them to organization B the target organization is not set during import but the organization of the source.
Workround: The import works if you manually change the value of the property
"organizationName" : "A",
to
"organizationName" : "B",
in every developer export file.