All line items on your Quote are showing a tax calculation despite using exempt item tax codes on the product record. The API response correctly shows the exemption but the Salesforce interface shows tax.
AvaTax for Salesforce Quotes
This issue is due to a missing parameter in the AvaTax for Salesforce configuration. The user must choose to save the document as Committed or Uncommitted.
Navigate to the AvaTax for Salesforce configuration.
Choose to save the document as either Committed or Uncommitted.
Save the record.