Array issue

in this scenario, i sift through the “in progress” and “completed” orders to add a tag on mailchimp if the total number of orders is equal to 1. basically, i want to track all new customers. i set up an iterator for the woocommerce “search for a customer” module that returns me the key “wc_order_count_wpuo” which is what i need.
i set up a filter that if “wc_order_count_wpuo” = 1, proceed to mailchimp.

i’m noticing that sometimes the array is empty. there are no bundles. how is this possible? thanks