Custom field for variation is not updated

I am using my own form elements for create new meta value for product varition, not functions like woocommerce_wp_text_input(). Reason is, that i need save array of values.
Problem is, that when i am trying save product, WooCommerce dont save variation, because dont see value change.

But, when i am use woocommerce_wp_text_input() functions, value change is detect and all is saved. I am using woocommerce_save_product_variation action.

Is there way, how to force variation saving?