I have setup a few search bars with filters. These seem to work well with one exception. If I do a 0 length search, the filters are ignored and everything is returned. The filters work fine if I am search on something greater than 0 length.
Under “General Options” -> “Logic and Behavior” I have set “Minimal character count to trigger search” to 0, as referenced in a few previous support posts.
I tried the page “sermons”, changed the “content to” filter to 01/01/2020, and I am seeing 10 tag results and 10 post type results: https://i.imgur.com/ejfHUHt.png
The first 10 results, which I marked with numbers on the screenshot are from taxonomy terms, those are not affected by the filters, as those are not post type results. You can turn those off on the General Options -> Sources 2 panel: https://i.imgur.com/ausuWOx.png
I believe those are the ones you are reffering to when there is no phrase entered.