WordPress error creating permalinks with custom post type

Hi,

I've added a custom post type that I called "author". When I add a new author, I can see that the permalink is /localhost/wordpress/author/james-jones. I added a new page with the author page as a template, and it displays the new posts correctly. However, if I click on one of the post titles, I get a 404 error.

I discovered that if I edit the author post and change the permalink to /localhost/wordpress/author/james_jones (with an underscore between the first and last names, instead of a hyphen) that I can then link from my author page to that post correctly.

How do I tell wordpress to use an underscore for a blank space when creating the permalinks? I don't want to have to change the permalink on each post by hand before I publish it.

[edited on 3/20/17] Okay, I found a little more information about this. It's the plug-in Custom Post Types UI that is forcing the use of the underscore. For some reason, the "art" post type created in the demo works correctly -- maybe because there are no spaces in the post titles? -- but my custom post type "author" uses the hyphen in the permalink and the underscore wherever the page is created. So I end up with a permalink looking like: ..wordpress/author/john-jones and an actual page that is ...wordpress/author/john_jones. So on my All Authors page, wordpress can't link to the permalink because that page doesn't exist.

I found a tutorial on the support site for Custom Post Types UI, but it doesn't give enough information for me to know how to fix the problem. The tutorial is at (http://docs.pluginize.com/article/27-changing-post-type-or-taxonomy-slugs). It recommends changing the Custom Rewrite Slug field to fix this problem, but it doesn't tell me what to change that field to contain.

Help! Vicki