This problem occurs for some plugins only.


We confirmed this problem for  plugin WooCommerce Ajax Mini Cart

Please, add following PHP code to functions.php  (or as snippet via https://wordpress.org/plugins/code-snippets/)

if ( is_admin() && isset( $_REQUEST['action'] ) ) {
    $action      = $_REQUEST['action'];
    $deny_prefix = "woo_amc_";
    if ( substr( $action, 0, strlen( $deny_prefix ) ) === $deny_prefix ) {
        add_filter( 'woocommerce_shipping_methods', function ( $methods ) {
            if ( isset( $methods['phone_orders'] ) ) {
                unset( $methods['phone_orders'] );
            }
            if ( isset( $methods['phone_orders_custom_price'] ) ) {
                unset( $methods['phone_orders_custom_price'] );
            }
            return $methods;
        }, PHP_INT_MAX, 1 );
       }
}