Got it, thanks for the link!
The Featured Image Caption plugin has always output the HTML for the caption, but until v1.26 of Founder it wasn’t visible due to a CSS styling conflict. When viewing the site, I am not seeing the HTML from the plugin being output. I’ve just tested the plugin with a fresh install of Founder and was able to view the captions on the page.
This means that there is a conflict with the Featured Image Caption plugin, and either the child theme or one of the plugins on the site. To debug this, you can temporarily switch from the child theme to Founder, and check if the captions then show. If they still do not, please try deactivating all plugins on the site, and reactivate one-by-one until the captions disappear again.
Give these steps a shot, and we will create a solution once we can find the source of the error.
Thanks!