WordPress in a subfolder?

Are you using WordPress to generate your home page as well (e.g. the WordPress Address (URL) is different from the Site Address (URL)), or only the entities under /blog?

WordPress is only being used under /blog (so WP address and site address are both /blog).

Since Breadcrumb NavXT is a WordPress plugin, and only knows about resources generated by WordPress, resources that are not generated by WordPress will need to be added with separate code. This article covers how to add a static breadcrumb to the beginning of a breadcrumb trail: https://mtekk.us/archives/guides/add-a-static-breadcrumb-to-the-breadcrumb-trail/

Awesome – that worked, thanks ??

I tried to override the ‘blog’ level title using this: https://mtekk.us/archives/guides/changing-the-home-breadcrumb-title/

But it also changed the title of the new home link I inserted, so I ended up with
Blog > Blog > Category > Post
instead of
Home > Blog > Category > Post

I tried altering the priority of the filters but it still got overridden?

The easiest option is to change the code adding the static home breadcrumb to use something different than array('home') (e.g. array('realhome')).