I have an issue that invalid customers are created on website sometimes. There is no email, phone number and address. Only first and last names in customer detail so it raises an error on our webhooks. I have asked the developer this problem and below is his reply. This makes no sense to me, but ask here first. Is statement below truth? Then why does Shopify creates invalid customers?
"This customer was automatically created by Shopify. What has happened is that someone checkout out without customer account and provided different shipping address and billing address. Shopify created user from the link from my comment based on shipping address and another one based on billing address."