I don't see any blank values anywhere. I have a single 'Assign Task' operation with the following config. I can send an lca if you like.
Initial User = 'Assign to Process Creator'
Form Data Mappings => input form variable = /process_data/myXFAForm
output form var = /process_data/myXFAForm
myXFAForm has as its Render Service/Operation = JdbService/queryMultipleToXml with the following settings:
datasourceName(literal)= IDP_DS
sql_info(literal)= select FIRST_NAME, LAST_NAME, CONTACT_INFO, ORACLE_USERID from TVS_TVAS_USER where STATUS='ACTIVE'
xml_info (literal) = root: tvasUsers; element: User; mapping: [{element_name=firstname, column_index=1, column_name=FIRST_NAME}, {element_name=lastname, column_index=2, column_name=LAST_NAME}, {element_name=emailAddress, column_index=3, column_name=CONTACT_INFO}, {element_name=tvasUserID, column_index=4, column_name=ORACLE_USERID}]
service output settings:
document=task/Document
