India Localization Payables - Unable to select tax authority supplier site when creating TDS tax

Hello Community.  We are setting up India localization Payables and need to define TDS taxes. However, the supplier site for the tax authority supplier cannot be selected on the 'Tax definition India localization form'. The form shows 'List of Values contains no entries' although there are supplier sites setup for this supplier.  I don't know if this is related, but we made sure to setup a NULL site under the Supplier Additional Information first per the India Localization Payables user guide instructions.  Does anyone have any suggestions?  Thanks in advance.