I had to add 3 new fields to an existing tblBooks & frmBooks. frmBooks initially updated two rows in table. Then when I added 3rd field, which was library, then the form stopped updating the table.
The three fields that are not updating in the tblBooks are: CallNumber, CallNumberSource, Library
However, Form is updating the query.
So, to recap: 3 new fields added to form. First couple of entries displayed in the table, then stopped. However, form continues to update query.