WooCommerce login on checkout issues

It seems you are not using default woocommerce checkout form. You are using multistep checkout form. Can you let me know which plugin you are using to create multi step checkout form?

Oh, I get it, it’s a paid one, so we’ll probably have to figure out with the developers on how to make it properly work or change our checkout: https://codecanyon.net/item/arg-multistep-checkout-for-woocommerce/18036216