Floating Social Plugin Inconsistencies: Showing for One Post but Not Others

I just installed the floating social plugin and I’m seeing some inconsistencies. I currently only have three posts on my blog. Out of the three posts, the social plugin only appears on one of them. It seems like it would work the same for all three posts or not at all. What are your thoughts?

It seems like the plugin is attaching to different things on each post, hence, it will show fine on one post, but then be completely off the page (or something like that) for another.

My settings are basic. These are regular posts. I do not have very many plugins, and the ones I have are either WPMU or well-used ones such as Contact Form 7.

Thanks for your help.