FEWC – WooCommerce Extra Checkout Fields not populating data into fields

Hi,
I have added a custom date checkout field with your plugin. After completing an order and entering a date into this field and submitting the order, no data is being updated to this field. Just ends up blank as per screenshot attached.
I have run a full conflict test and even copied the site to a different web host but I’m still not having any luck getting the custom checkout field to populate.
Any help would be much appreciated. I’m planning on using this plugin with your Email Template Customizer for WooCommerce plugin.

Many thanks in advance.

Leo George