Why are exempt sales taxing in my import?

We've imported many transactions with the entity use code G for resale but are seeing tax as calculated.

Please be sure that your exemption management system settings are set to Optional if you are attempting to exempt a customer that has no exemption certificate on file in our system.

If you are set to Required it will ONLY exempt a transaction for a customer who has an exemption certificate in our system associated with their customer code.