Hi @rtstc2000,
When you had your images moved to a CDN, it’s likely they were given a slightly different URL, and may have been de-indexed if they no longer existed at their old addresses. For example, it’s common to set up a subdomain on your site to handle redirects to your CDN (Eg. https://cdn.yoursite.com). I’d imagine your web guy fixed this by regenerating your sitemap to update your image URLs.
In regards to indexing your slideshow images, I don’t believe it would be possible with the slideshow in the original NextGEN codebase (v1.x.xx), as the images are pulled in dynamically (they don’t appear in the page’s HTML source).
It should be possible with NextGEN 2.0’s slideshows however (as they do appear in the source), but I doubt my technique in the thread you referred to would be compatible with this completely new codebase.
In regards to indexing images in Fancy Gallery, I would recommend contacting the developer, as he’d be much more familiar with his code (I’ve only just heard about it).
I hope this helps!
Cheers,
Mark.