DuplicateValue error when trying to update the name of an organization using API

Using the below endpoint I am getting DuplicateValue error when I try to update the name of the organization. I have been using this endpoint successfully for a long time, but not for name changes. Any help appreciated

Endpoint:  /api/v2/organizations/orgid.json

JSON I am sending:

zOrgFields = { 'organization':
                     {'name': CompanyName,
                     'organization_fields':
                        {'grx_id':CompanyGRXid,
                         'company_address':ZenCompanyAddress
                         }
                      }
                     }