Hi,
Thank you for the details. Unfortunately I cannot tell by only the front-end and screenshots, but most of this configuration seems to be okay.
I am going to guess, but the most probably issue is, that the index table engine is probably not selected under the search instance General Options -> Sources panel: https://i.imgur.com/mtjeDte.png
Other issues might be related to exceptions, excluded keywords etc.. If the index table engine is in use, and it does not work, you can add temporary back-end details, and I will check the configuration directly.