It doesn’t appear a tag can be an external link […] or internal link [[…]]. Also, it seems to be easier to me to add tags and other properties in preview mode so I don’t have to think about how they are formatted.
I used an example Templater template to build from, and it had the <% — %> in it, so I left it. (Still learning my way around the Templater syntax.)
But, when it changed it to just three hyphens, the tags entries began working.
Not sure why Templater wanted to put the three hyphens in a code execution block. But, I’ll change them all in my vault and see if that takes care of the problem. Thanks all!