Why are my value modifiers not working?
Value modifiers need to be entered like this:
The following two things often go wrong:
The values you enter in a facet’s “Value modifiers” field need to be each on a separate line in the form field. Do not put them on one line with commas or add commas to each line.
The values also need to match the label (not the slug) of the value exactly, including spaces and capitalization.
For example, if you have a category called “Fall Collection”, the value entered in the “Value modifiers” field needs to be exactly that: Fall Collection.
If you have not modified the facet values with output hooks like facetwp_facet_display_value, the quickest way to determine the labels is to look at the facet value labels themselves: the labels beside the checkbox or radio button, or the options in the dropdown. Make sure to check if capitalization is not changed with CSS, for example with text-transform: lowercase.