Contents of array is not displayed within the response when using oneOf

When a schema has an array, the contents of the array are shown in the right hand side display window when set as a response, however when oneOf is used it shows as an empty array.

openapi: "3.0.2"
info:
  title: API Title
  version: "1.0"
servers:
  - url: https://api.server.test/v1
paths:
  /test_oneof:
    get:
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                oneOf:
                  - $ref: '#/components/schemas/a'

  /test_without_oneof:
    get:
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/a'

components:
  schemas:
    a:
      type: array
      items:
        type: object
        properties:
          b:
            type: string

The details are shown in the centre panel regardless of whether oneOf is used or not.

Below shows that this is valid and displayed correctly in the swagger editor

(edit: added swagger editor screenshot)