Hi!
I haven’t been able to log-in with the details, but I think I know what you are looking for.
By default, the plugin does not exclude items, that does not belong to any category/term, as those have no connection to the filter itself.
You can change that (an other things as well) on the Frontend search settings -> Andvanced panel: https://i.imgur.com/AwfGVq1.png
