User has to be in a Group that is tax exempt.
They add items to their cart without logging in first.
They log in on the OnePageCheckout.
Sales tax is erroneously added no matter what their address is. That's people in a tax exempt group that do not reside in a state to be taxed!
Discounts for their group are applied correctly. If they add more items to their cart, no more sales tax is applied.
Can someone please help with this?
These are my settings:


Example of messed up invoice:
