In the index table of the plugin I added the taxonomies (productcategory, keywods, location) but the keywords or products do not appear in the search results.
Thank you for the proper details, it helps me a lot!
The problem was, that the index table engine was not enabled, and the product custom post type was not selected on the search instance options: https://i.imgur.com/wNAYxar.png
I have changed it for you, now it should start returning products as results as well.
The Index Table options are sort of ‘global’, but not automatically enabled for the search instances by default – as it is possible to create multiple search bars.