I’m having this same issue. It only happens on a sub-site in my multi-site config. It seems it is dragging the slug from one of my old posts into the URL being populated in the secondary site’s admin bar. And it isn’t on every option in the bar either. Every link under “My Account”, top level on “My Sites” and everything under “Notifications” dropdowns.
I was wondering myself how to do this. But the instructions above do not apply to BuddyPress, since the “Front Page Displays” settings are all missing from the main BuddyPress site under Settings.
