Default Enum Values in OneOf Definitions do not appear in form data submissions

[AScully24]

Prerequisites

• [x] I have read the documentation;
• [x] In the case of a bug report, I understand that providing a SSCCE example is tremendously useful to the maintainers.
• [x] Ideally, I'm providing a sample JSFiddle or a shared playground link demonstrating the issue.

Description

When submitting an enum value from a field contained in a oneOf definition, the default value is not included in the formData property after submission.

JS Fiddle Example

Playground

Steps to Reproduce

1. Use the following schema in the Playground / JS Fiddle:

{
  "title": "OneOf Enum Bug",
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "Name": {
      "type": "string"
    },
    "one-of-example-field": {
      "oneOf": [
        {
          "$ref": "#/definitions/MyDefinition",
          "title": "My Choice"
        }
      ]
    }
  },
  "required": [
    "Name"
  ],
  "definitions": {
    "MyDefinition": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "this default enum will not be in the submitted form data": {
          "type": "string",
          "enum": [
            "foo-bar"
          ],
          "default": "foo-bar"
        },
        "Header Key": {
          "type": "string"
        },
        "Header Value": {
          "type": "string"
        }
      },
      "required": []
    }
  }
}

2. Fill in any fields
3. Submit the form

Expected behavior

Form data should contain all fields, including the default enum value described in MyDefinition

Actual behavior

The default value is not present

Version

2.5.1