rmgreg

Figured it out:
Even if the tax value for an order is 0.00, Automated Taxes may be working correctly. If your store is based in the United States, you only need to collect sales tax from customers in locations where you have a “tax nexus,” which typically means a physical presence. WooCommerce Services uses your store address (WooCommerce > Settings > General) as your “tax nexus”.

https://woocommerce.com/document/woocommerce-shipping-and-tax/woocommerce-tax/