[Plugin: NextGEN Gallery] Attaching slideshow to a post to be indexed by Google

This is my first post on www.ads-software.com.

I recently rebuilt my website with WordPress. I am using the Nextgen Gallery slideshow to display images in my posts.

Unfortunately, I recently discovered Google is not indexing my images and that the slideshow is in no way, as read by Google, related to its post.

I have attempted to fix the indexing issue with the Yoast SEO pluggin, however, the XML site map appears to only index the image tags. I cannot see how this resolves the issue; is there something I’m missing?

Providing Yoast SEO can solve the indexing issue, is there a way to “attach” a slideshow to a post or perhaps attach the gallery to the post?

One of my pages: https://www.autovoce.com/2011/09/white-lamborghini-gallardo-550-2-underground-racing-twin-turbo/

I need help, my site has lost most of its traffic because of this.

Nicholas

https://www.ads-software.com/extend/plugins/nextgen-gallery/