If you’re using the plugin “Instructor Role for LearnDash” by WisdmLabs, you might want the “Instructor” to access some backend pages in the front end, however, due to WisdmLabs coding, the instructor plugin blocks all the admin pages that they don’t want the instructor to see and they block it in their code regardless of the user capabilities. The user could have all the existing capabilities assigned, but they still wouldn’t be allowed to see the page.
In this case, you need to contact WisdmLabs and ask them how to allow the instructor to access a specific page, and they should provide the solution for you. We will need to rely on their side to make their plugin work with WP Frontend Admin.