CPT drop downs showing "no results"

Hi,

We have updated the dropdown to select2 for Invoicing and UsersWP plugins also. The post grid plugin conflicts with our plugin and is causing an issue. So you can use the following code in your functions.php file of currently active theme or using snippet plugin to fix this:

/**
 * Fix select2 conflict with Invoicing & Post Grid (post-grid) plugin.
 */
function wpinv_post_grid_select2_conflict() {
    $screen    = get_current_screen();
    $screen_id = $screen ? $screen->id : '';

    if ( wp_script_is( 'select2', 'enqueued' ) && wp_script_is( 'select2.min', 'enqueued' ) ) {
        if ( $screen_id && in_array( $screen_id, array('wpi_invoice', 'edit-wpi_item', 'edit-wpi_discount', 'wpi_item', 'wpi_discount', 'invoicing_page_wpinv-settings', 'invoicing_page_wpinv-subscriptions', 'invoicing_page_wpinv-reports') ) ) {
            wp_dequeue_script( 'select2.min' ); // Dequeue Post Grid select2 on WPI pages
            wp_dequeue_script( 'post_grid_admin_js' );
        } else {
            wp_dequeue_script( 'select2' ); // Dequeue WPI select2 on non-WPI pages
        }
    }

    if ( wp_style_is( 'select2', 'enqueued' ) && wp_style_is( 'select2.min', 'enqueued' ) ) {
        if ( $screen_id && in_array( $screen_id, array('wpi_invoice', 'edit-wpi_item', 'edit-wpi_discount', 'wpi_item', 'wpi_discount', 'invoicing_page_wpinv-settings', 'invoicing_page_wpinv-subscriptions', 'invoicing_page_wpinv-reports') ) ) {
            wp_dequeue_style( 'select2.min' ); // Dequeue Post Grid select2 on WPI pages
        } else {
            wp_dequeue_style( 'select2' ); // Dequeue WPI select2 on non-WPI pages
        }
    }
}
add_action( 'admin_enqueue_scripts', 'wpinv_post_grid_select2_conflict', 100 );

Let me know if it resolves your issue or not.

Regards,
Patrik