Reduce WooCommerce product stock from WP All Import XML

Question

In WooCommerce with WP All Import, I'm using the following code to reduce the product stock quantity, but I'm getting 0 stock quantity (so it doesn't work):

function reduce_stock_based_on_custom_field( $product_id, $xml, $update ) {
    // Get the value of custom field 'bmind_stock'
    $bmind_stock = get_post_meta( $product_id, 'bmind_stock', true );

    // Check if 'bmind_stock' is 0 and reduce stock accordingly
     if ( $bmind_stock === 0 ) {
        // Get current stock
        $current_stock = get_post_meta( $product_id, '_stock', true );

        // Calculate new stock after reduction (e.g., reducing by 1)
        $new_stock = ($current_stock) - 1;

        // Update product stock
        wc_maybe_reduce_stock_levels( $product_id, '_stock', $new_stock );
    }
}

add_action( 'pmxi_saved_post', 'reduce_stock_based_on_custom_field', 10, 3 );

For example: If the product stock quantity is 6 and if I have for bmind_stock custom field a value of 0, I need to set the product stock to 5, so to reduce it to 1.