Add custom filters to your List Page.
There already exists an "empty filter" (/sitecore/content/Repository/searchgenres/empty filter) that you can add if you want no filters at all to show.
You are adding filters manually. This means the filter does not "read" the tags that are on all the pages on your list page as would be the case if you didn't add this searchgenre option and let the tags show automatically (a feature built into this template). What I mean to say is, if you've added a tag to your filter and none of the pages pulled in to your list page have this tag, the search will come up empty. Similarly, if you've forgotten to add a tag to your filter then obviously you won't be able to filter pages on this tag. SO, if you've created a new tag in the meantime, don't forget to add it to your searchgenre filter!
See example of a searchgenre filter below!