Not able to load two records for two tax partners to be used for different business units

Summary:

Not able to load two records for two tax partners to be used for different business units through "Manage Tax Partner Integration in a Spreadsheet"

Content (please ensure you mask any confidential information):

I am trying to load two records - one for Vertex Tax Partner to be used in the United States Business Units and another for OneSource Tax Partner to be used in the Middle East Business Units through "Manage Tax Partner Integration in a Spreadsheet". But it is only keeping the last record in the database (even though I am trying to load both together) and hence only one Tax Partner is working at a time.