Hello @chas901
Thank you for reaching us out.
I am sorry for the trouble that our plugin may have caused. Unfortunately, I was unable to replicate the issue locally. Also, I can see your all listing and single location page are working fine. All these pages uses the same layout and if one of them works then all the pages should work fine too. I would request you to share some more context of the situation.
1. May I know if there is any additional customization that you made in the single category page?
2. How did you create the single category page? (divi builder, elementor or shortcode?)
3. Are you using the correct shortcode? [directorist_category]
In addition, please try creating a new single category page using the following shortcode [directorist_category] and assign it in settings > pages, links, and views. Make sure not to use any 3rd party plugin features or any customization [For debugging purpose]
Let us know the results.
Regards,