[BUG] - Default Picklist on Custom Questions

[rdblake21]

Describe the bug
When creating a default value when the Question Type is Picklist, the value doesn't move the the registration record, particularly when the field is NOT visible.

Conversation chain in the community - https://trailhead.salesforce.com/trailblazer-community/feed/0D54V00007er0eR

To Reproduce
Steps to reproduce the behavior:

1. Create a question question with a field type of Picklist and the "visible" field as False
2. Map the question to the appropriate registration record value
3. Register from the guest user perspective on the registration page
4. See the error in that the default value of the hidden field where the custom question field type is picklist doesn't flow to the registration.

Expected behavior
Default value should flow to the registration regardless of field type and regardless to is the value is hidden or visible.

Screenshots
See community post - https://trailhead.salesforce.com/trailblazer-community/feed/0D54V00007er0eR

Additional context
When changing the field type to "Text" it works as a hidden field.