Cannot disable "customer accepts marketing" when creating new customers with liquid form

6 1 2

I have created a notification form when a product is out of stock so the customer can request to be contacted when that item is back in. This form just creates a customer account using the email address they supply. The store owner would also like to use this as away to build their email list. I have included the customer accepts marketing input so the customer can check the checkbox if they would like to receive emails in the future.

The issue I am having is no matter how I format this checkbox input, Shopify ALWAYS sets the email marketing status as "subscribed" despite the fact that the checkbox is unchecked.

This is how I have the initial checkbox setup. It is unchecked upon page load. After submitting the form a customer account is successfully created with the email address but the marketing is accepted anyway.

<input id="customerAcceptsMarketing" type="checkbox" name="contact[accepts_marketing]" />

How can I ensure the customers account reflects the status of their selection? Every article I have read is using contact[accepts_marketing] as the correct value to send. Do I need to specifically send a custom attribute I am not aware of that tells Shopify to not enable subscriptions?