@wes_w I have been watching this thread today. Have you had any luck with support? I have a few customers with nexus in IL but have not mentioned any issues.

@NetSuite_Sherpa Even though NetSuite's e-fix changed the behavior of how my setup worked (and I worked with their support to set it up originally), it turned out to be a simple solution. The home tax group for Illinois was set to empty, and it just needed to be populated with the custom group set up for Illinois.