This isn't a bug, but something to consider for the next update.
a13fe-post-list short code should allow for a default selected category.
Currently, you can either list all Works, and show the filter, or list works from only a selected category or categories. But you can't show only some works by default then allow the user to choose all categories.
[a13fe-post-list type="work" orderby="title" posts="5" columns="2" filter="1" categories="featured, digital, print" defaultcategory="featured"]
(And an "All" filter would appear, but "Featured" Would be selected.)https://rifetheme.com/help/docs/content-management/shortcodes/post-list/