That was it. I removed single.php from the child theme and the related images came back. I updated single.php in the child theme to include the new code for related images from the latest Dante update, so I was able to use my modified single.php and still have the related images work as expected.
Many people don’t realize that just because you are using a child theme you are not always safe from theme updates crashing your code. If you are replacing core files there is a good chance these files will be modified by the theme authors and could break your child theme versions. I should have thought of this before I started the thread. Oh well, maybe it will help someone else.
You guys (or girls) are always on top of things and I thank you for the great support and a great theme.
Cliff Dugan
QuesTronix Software