This isn't a bug - just a suggestion for improved UX.

In System Settings > Roles and Permissions > Permissions Editor, after I clicked a path to view pages and role assignments, I couldn't figure out how to return to the previous view of all paths. I finally saw the Back button near the page management functions at the top (see attached screenshot). I may not be the only frustrated user who didn't immediately see the navigation, so my suggestion is to format the Back button so it's more noticeable.