Saving edited Metadata tags

Using Mac OS 10.12.6, Audacity 2.2.2
In the Edit/Metadata section: I’m able to add 2 extra lines for ISRC and UPC numbers, but when I save as new file name OR replace the Tags.xlm file it’s not saving the new 2 lines I’ve added. What am I doing incorrectly?

When saving metadata templates, custom tags (left column) are only saved if they have a tag value (right column). The tag value can be just a place holder, such as a space character, but there has to be something in the right hand column.