When selecting the “Show Feedback” category, you’re taken to a page with a notice saying:
There are no more Show Feedback topics. Why not create a topic?.
The “Latest” nav button is active by default, so it seems to be a problem where topics are not displaying if ordered by the latest new topic, as is set to default.
Clicking on the “Top” button does display the topics in the category (although obviously organised by the “Top” topic, rather than latest).