Unable to set default for radio button

We want to have the first radio button for a field to pre-selected when the checkout page loads. But setting Default Value in the editor does not select the radio button. Isn’t this how we are supposed to set the default?

Steps to re-produce:
– create new field with Type=radio
– create an option with text and value = “test”
– set default value to “test”
– Save
– view checkout page
– radio buttons are displayed but none are selected