That's hard to confirm without actual steps to reproduce, but unity will display the expander only if there are >6 results in the model, so it's more than likely that the backend model is fine.
What happens when you get this bug and try to expand the category? ** Changed in: unity8 Status: Confirmed => Incomplete -- You received this bug notification because you are a member of DX Packages, which is subscribed to unity-lens-applications in Ubuntu. https://bugs.launchpad.net/bugs/1225391 Title: Installed Applications is blank after doing a search Status in Unity Applications Lens: Confirmed Status in The Unity 8 shell: Incomplete Status in “unity-lens-applications” package in Ubuntu: Confirmed Bug description: Steps: 1. Search for applications in the home scope 2. Dismiss the search Result: sometimes the Installed Applications section is then blank (see attached screenshot) To manage notifications about this bug go to: https://bugs.launchpad.net/unity-lens-applications/+bug/1225391/+subscriptions -- Mailing list: https://launchpad.net/~dx-packages Post to : dx-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~dx-packages More help : https://help.launchpad.net/ListHelp