Afterword

If anyone else needed to correct this particular issue, you can dequeue the responsible CSS (copy any CSS you need to your own stylesheets if necessary). Though it would be preferable to have this problem corrected in the plugin.

Add the following to your custom functions (or custom plugin):

function remove_sf_styles(){
	wp_dequeue_style( 'searchandfilter' );
}

add_action('wp_print_styles', 'remove_sf_styles', 20 );

@penn_star how did you go? It looks like your sites have been corrected. I’m having this problem too but I can’t seem to find the reason for it. The problem seems native to the search&filter plugin?