Are you able to send me a live link/URL to your search page so I can take a look?
Are you trying to search words in the categories using the Text search box? If so, this might help:
Our plugin does not directly allow you to do text searches of individual Post Meta data. The Search & Filter Pro Text Search field uses the standard WordPress search, so looks only in the Post Title and Content. To help you control this better, on the form’s Advanced settings tab you will see settings for Relevanssi.
The documentation for this is here:
https://www.designsandcode.com/documentation/search-filter-pro/3rd-party/relevanssi/
You would need to install and activate the free Relevanssi plugin as well.
Then set it up and build its index.
Some way down the form is a single entry setting to support custom fields. Taxonomies are more easily set up.
Note that we do not support any of the formatting options in Relevanssi. We use it to allow you extend what is searched, and what relevance is placed on the content.
.
