A custom attribute was added to the purchase order and confirmed populated. When printing the purchase order the attribute defaults to its null value test.
When the custom attribute was created on the class, a special character was used in the Attribute name which carried over into the Member name and Column name properties. The special character was an underscore "_". When trying to print the report this character somehow confused the report mechanism so it was returning a null value even though the attribute was populated in the database and visible in the UI and from table configurations.
If the attribute is a newly created attribute not yet populated in the database simply remove the special character, underscore "_", from the Attribute name, Member name and Column name of the custom attribute. Next update the Report removing the original attribute and saving the report. Restart the application server. Update the report one more time including the newly renamed attribute.
If the attribute is already populated in the database, you will need to create a new attribute without the "_" special character in the name, write a script to copy the data from the original custom attribute into the new one, then update the report and anywhere the old custom attribute is displayed in the UI with the new custom attribute to the report. Once the script has been run and the report fixed, the old custom attribute with the special character should be deleted from te environment.