Breadcrumb navigation in forum is incomplete - link to highest level is missing

When I'm viewing a post (and also right now when I'm typing a new post), the breadcrumb navigation is missing the actual link to get back to the specific forum. Only "forum" has a link inderneath, but not "Site Improvemtns". Quite annoying as one always has to go back to the forum and then into the appropriate subforum instead of getting there directly.

Here's a link:

Here's no link:

Here neither: