Group browsing bug Answered
There's no way to browse non-featured groups without editing the URL and removing the "feature:true" str.
Go to menu: "Community: Groups", and only featured groups are returned.
Click group in exploring: group : featured and "No instructables found!" Click featured, and featured instructables are returned. So those links return only instructables, not groups.
If you select any of sort by: recent | views | rating links, the "featured:true" tag remains in the URL, and only featured groups are displayed.
(I submitted a similar bug report a month or two ago, but the behavior is the same.)