Hi!
The problems are the exclusions/inclusions set. Make sure to clear both the excluded and included categories here: https://i.imgur.com/kCg0Enq.png
Those are not needed in your case, as the filter will always limit the results to the selected category.
To center the filter box, use this custom CSS:
[html]div.asp_w.asp_sb.searchsettings form {
justify-content: center;
}[/html]
..aslo, if you want to change hte width of the select box to match the container width, you can use this one as well:
[html].asp_sb fieldset {
width: 100% !important;
}[/html]