Hi,
I’m having the same problem.
No filter (checkbox, search, price, brand) works.
To repeat the error:
Install the plugin;
create a filter;
Leave all the default options;
On the Database Query tab, use the post type “Product”, Main Query, Product Archive;
After that, create the category items (or whatever);
Source of options: Taxonomy;
taxonomy: product category;
I already try to delete the plugin and install again, but after install all the settings are saved (and i cant delete it).
Thank You!