Rendering of nested objects break when using `allOf` in the main schema

Q&A (please complete the following information)

• OS: Windows/OSX/Ubuntu
• Browser: Edge
• Version: Version 109.0.1518.78 (Official build) (64-bit)
• Method of installation: npm (but also happens in online editor)
• Swagger-UI version: v4.15.5
• Swagger/OpenAPI version: OpenApi 3.0.1

Content & configuration

Broken example Swagger/OpenAPI definition:

openapi: 3.0.1
info:
  title: Testapi
  version: v1
paths: {}
components:
  schemas:
    SubjectBase:
      type: object
      properties:
        naam:
          type: string
          nullable: true
    TestSubject:
      required:
        - $type
      type: object
      allOf:
        - $ref: '#/components/schemas/SubjectBase'
      properties:
        sum:
          allOf:
            - $ref: '#/components/schemas/PeriodicGegevenAmount'
          description: One time payment
          nullable: true
      additionalProperties: false
      description: Test class
      discriminator:
        propertyName: $type
    Percentage:
      required:
        - amount
      type: object
      properties:
        amount:
          maximum: 100
          minimum: -100
          type: number
          format: double
      additionalProperties: false
    Periodic:
      required:
        - $type
        - einddatum
        - ingangsdatum
      type: object
      properties:
        startdate:
          type: string
          format: date
        enddate:
          type: string
          format: date
      additionalProperties: false
      discriminator:
        propertyName: $type
    PeriodicAmount:
      required:
        - $type
      type: object
      allOf:
        - $ref: '#/components/schemas/Periodic'
      properties:
        factor:
          allOf:
            - $ref: '#/components/schemas/Percentage'
          nullable: true
      additionalProperties: false
      discriminator:
        propertyName: $type
    PeriodicGegevenAmount:
      required:
        - isWaardevast
        - periodieken
      type: object
      properties:
        periodieken:
          type: array
          items:
            $ref: '#/components/schemas/PeriodicAmount'
        isWaardevast:
          type: boolean
      additionalProperties: false
      description: The amount and period to which this amount applies

Working example Swagger/OpenAPI definition:

openapi: 3.0.1
info:
  title: Testapi
  version: v1
paths: {}
components:
  schemas:
    SubjectBase:
      type: object
      properties:
        naam:
          type: string
          nullable: true
    TestSubject:
      required:
        - $type
      type: object
      allOf:
        - $ref: '#/components/schemas/SubjectBase'
      properties:
        sum:
          allOf:
            - $ref: '#/components/schemas/PeriodicGegevenAmount'
          description: One time payment
          nullable: true
      additionalProperties: false
      description: Test class
      discriminator:
        propertyName: $type
    Percentage:
      required:
        - amount
      type: object
      properties:
        amount:
          maximum: 100
          minimum: -100
          type: number
          format: double
      additionalProperties: false
    Periodic:
      required:
        - $type
        - einddatum
        - ingangsdatum
      type: object
      properties:
        startdate:
          type: string
          format: date
        enddate:
          type: string
          format: date
      additionalProperties: false
      discriminator:
        propertyName: $type
    PeriodicAmount:
      required:
        - $type
      type: object
      allOf:
        - $ref: '#/components/schemas/Periodic'
      properties:
        factor:
          allOf:
            - $ref: '#/components/schemas/Percentage'
          nullable: true
      additionalProperties: false
      discriminator:
        propertyName: $type
    PeriodicGegevenAmount:
      required:
        - isWaardevast
        - periodieken
      type: object
      properties:
        periodieken:
          type: array
          items:
            $ref: '#/components/schemas/PeriodicAmount'
        isWaardevast:
          type: boolean
      additionalProperties: false
      description: The amount and period to which this amount applies

Describe the bug you're encountering

When using the first YAML which contains an allOf to SubjectBase in TestSubject you will need see the properties correctly when you open periodieken in sum (see also screenshot).

To reproduce...

Steps to reproduce the behavior:

1. Go to 'https://editor.swagger.io/'
2. Paste in the YAML
3. Open the schema TestSubject and keep opening until you come across the property factor
4. See that properties are not being rendered

Expected behavior

You should see the properties of nested objects like in the working screenshot.

Screenshots

Not working:

Working:

Additional context or thoughts

This might have broken before 4.15.5 . We recently got a new customer which was looking at the swagger and then we discovered it has broken. A year ago it still worked.

Reproduce the issue in https://editor.swagger.io/ by pasting the broken YAML and opening TestSubject through sum, periodieken, and factor. Trace the schema-rendering path for nested allOf references and compare it with the working YAML. Done means the nested object properties render in the broken example as they do in the working example.