Q: Left course panel stuck in library view

In Library view, I keep getting a left panel containing outline or posts from recently subscribed to courses. The panel goes if I switch to Catalogue, but reappears as soon as I go back to Library. I can't get rid of it except by deleting the courses, but then it reappears with the contents of another course. Anyone else had this?

(and ps can anyone tell me how to report a bug to Apple? thankyou!)