Thanks Robby, but I am not using WPML. From my research it looks like it is saving “all” as the taxonomy when none are selected but nothing is returned since it isn’t a real taxonomy.
I do have some special cases in my setup – specifically I’m using a wrapper field type on some ACF fields – but for me I was able to get around the problem by adding a filter on load_field.
if ( $field['taxonomy'][0] == 'all' ){
unset( $field['taxonomy']);
}
