The link for reporting a bug is https://github.com/tom-james-watson/old-reddit-redirect/issues/.

In what way is it not working? Some users recently seem confuses by the fact that subreddits on Old Reddit can still have custom stylesheets and so can vary in how they look. You can turn these off in your user preferences in Reddit itself.

Some other users seem confused by the fact that there are now 3 major Reddit designs. This extension is only to load Old Reddit (old.reddit.com).