Why aren’t any posts showing up in my featured slider?
Check to see that the slug for your featured tag is “featured” and not “featured-2” or something else. This usually only happens if you have a category already named “featured”. Categories and tags in Wordpress cannot have identical slugs. Change the slug of your featured category to “featured-3” or something else, and then change the slug of your featured tag to “featured” and your slider should show up.