Came across this while setting up for a tutorial on WPSP.
I have two WPSP lists, both using a category, with one of them to be used for a “featured post”. On the home page, I used the WPSP shortcode for the “blog” category to be displayed underneath the “featured” category shortcode. So far, so good.
What happens is that I added a WPSP widget to the Right Sidebar and Footer 1 (using GeneratePress for the theme, of course :)) and selected the “featured” list from the widget. Still doing fine, shows up nicely.
However, when one selects that post and ends up on the single post page, the widgets then display the “Sorry, no posts were found.” message. Tried using a tag instead, but the same thing. Perhaps it’s “just the way it works” ??