Export of Custom Fields

@ Margo

Could be the space in the words is not being liked. Try this:

// Register the custom fields CSV Import mapping options and processing callback.
add_filter( 'cncsv_map_import_fields', 'cncsv_header_name' );
add_action( 'cncsv_import_fields', 'cncsv_process_import', 10, 3 );

function cncsv_header_name( $fields ) {

    // The field_id should match exactly the field id used when registering the custom field.
    $fields['branch_logo']     = 'Branch Logo';
    $fields['marker_location'] = 'Marker Location';

    return $fields;
}

function cncsv_process_import( $id, $row, $entry ) {

    // The field_id should match exactly the field id used when registering the custom field.
    $logo = $entry->arrayPull( $row, 'branch_logo', '' );
    $logo = cnFormatting::maybeJSONdecode( stripslashes( $logo ) );

    $marker = $entry->arrayPull( $row, 'marker_location', '' );
    $marker = cnFormatting::maybeJSONdecode( stripslashes( $marker ) );

    cnEntry_Action::meta(
        'update',
        $id,
        array(
            array(
                'key'   => 'Branch Logo', // The field_id should match exactly the field id used when registering the custom field.
                'value' => $logo
            ),
            array(
                'key'   => 'Marker Location', // The field_id should match exactly the field id used when registering the custom field.
                'value' => $marker
            ),
        )
    );

}