If you click a tag on the result/preview page (in mobile Firefox), the result list is filtered by the tag (you get a new/shorter result list with an updated result number).
But because you are still on the preview page you don't immediately see this as it's done in the background.
But once you close the preview page (with the big arrow on the top/left of the preview page) you will see the updated result list and number.
Of course, this is a design flaw, we should automatically close the preview window once you select a tag to immediately show you the updated result list.
In the desktop version, this is no issue, as there result list and preview window are always simultaneously visible.
But because you are still on the preview page you don't immediately see this as it's done in the background. But once you close the preview page (with the big arrow on the top/left of the preview page) you will see the updated result list and number.
Of course, this is a design flaw, we should automatically close the preview window once you select a tag to immediately show you the updated result list. In the desktop version, this is no issue, as there result list and preview window are always simultaneously visible.