You are seeing orders come in without sales tax on them. These orders were created using the Scanco barcode module. Then when you push them into data entry you see they do indeed now have tax.
Scanco Barcode module
This was a reported issue of compatibility within the Avalara Avatax connector for Sage 100 and the Scanco barcode module.
This was reported in version 5.00.9.0 || 06.0 DSD of the integration
The issue has since been fixed in the most recent available version of this integration at the time of this article's publishing.
To resolve this issue please upgrade to the most recent version of the Avalara Avatax integration for Sage 100 and your specific year of the product.