Hi Joy,
That you for your comment and pointers. I’ve checked my tags and none of them start with a number and they all only include letters and are unique.
I update the post as soon as the tag is applied. Then I preview it, and it works, only for it to not work when I apply the next tag.
For additional insight, I did a screen capture showing the issue…
YouTube Video Showing The Issue
Does this shed any light into what’s going wrong?