Post URL Format is not "%t" it is header-xxxxx

Site URL: https://www.tablaturedude.com/blog/header-caf9a

I have the blog settings "Post URL Format" set to "%t", but the URL ends up looking like this:

https://www.tablaturedude.com/blog/header-caf9a

I want it to look like this:

https://www.tablaturedude.com/blog/purple-rain-kent-nishimura-guitar-tablature/

Short of editing all urls by hand, is there a way to go back and fix all of these automatically?  and how do I prevent this from happening in the future?

EDIT:  I may have figured this out.  It seems that it is because I am using a "template" that I start by making a duplicate. the template has a title called Header.  so when I duplicate it, I assume it is generating a "header-uniqueID" as the url.  and when I make an actual title, it is not not picking it up.