The website has a heading 1 for the page title and breadcrumbs. Both the page heading and the breadcrumbs think that any page within the bbpress forums is within the “blog” section. So the heading 1 says “blog” and the breadcrumbs say home > blog > topic name
Note: the breadcrumbs that come with bbpress work fine.
One other problem that may be related is that wordpress also triggers the Blog menu item link as the current_menu_item (thus highlighting it in the main menu). I can override this with css so I am not overly worried about it but thought it worth mentioning. I notice that this problem is actually a reported bug in bbpress and is being worked on.