An estimate was created and when converted to an invoice, the tax amount changed. The estimate shipped all items from the default warehouse and Avatax-POS was used. The invoice had multiple sites used and used Avatax-POS.
The esitmate had the correct tax while the invoice had a different amount.
Quickbooks Enterprise with Advanced Inventory
When using Avatax-POS, tax is based on origin. When using multiple sites on an invoice, you have multiple origins and addresses are passed at the line level resulting in different tax from the default location. If using POS, ALL lines MUST come from the same site.