If capabilities are granted to instructors to edit their own courses & add/modify/delete units in them, they should be able to access their own courses. But they can't access their own courses unless the capability to also create new courses is granted. That doesn't make sense.
Below are screenshots to show that all capabilities have been granted for Instructors to access & edit their own courses, but they don't have access to them in the site admin.
Also, if capabilities are granted to Instructors to only add/edit/delete Units in their own courses, the ability to create or edit courses should be blocked.