On the new course outline page, there are two <main> elements:
HTML5 only allows for one, and this impacts accessibility. We need to consolidate these into one element. Because of the id and tabindex attributes on the second one, I suggest demoting the first main element to a div. The role=main is redundant, so that can be removed alltogether. I recommend adding an aria-label="Content" to the remaining main element so it is identified as Main Content to SR users.