Incorrect dataType output when using a $ref to an enum as the schema in the requestBody

The snippet below from an OpenAPI document shows a parameter in path and request body whose schemas are both references to an enum StuffType:

openapi: "3.0.0"
info:
  version: 1.0.0
  title: Swagger Petstore
  description: A sample API that uses a petstore as an example to demonstrate features in the OpenAPI 3.0 specification
  termsOfService: http://swagger.io/terms/
  contact:
    name: Swagger API Team
    email: apiteam@swagger.io
    url: http://swagger.io
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0.html
servers:
  - url: http://petstore.swagger.io/api
paths:
  /stuff/{stuffType}:
    post:
      tags:
        - 'stuff'
      description: "Do some stuff"
      operationId: "doStuff"
      parameters:
        - name: "stuffType"
          in: "path"
          required: true
          schema:
            $ref: '#/components/schemas/StuffType'
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/StuffType'
      responses:
        '200':
          description: 'A response'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StuffType'
components:
  schemas:
    StuffType:
      type: string
      enum:
        - A_1
        - B_1
        - D_2

This is the method generated by jaxrs-spec:

@POST
@Path("/{stuffType}")
@ApiOperation(value = "", notes = "Do some stuff", response = StuffType.class, tags={ "stuff" })
@ApiResponses(value = { 
    @ApiResponse(code = 200, message = "A response", response = StuffType.class)
})
public Response doStuff(@PathParam("stuffType") StuffType stuffType,@Valid String body) {
    return Response.ok().entity("magic!").build();
}

While the generated method uses StuffType as the type for the path parameter, String is used as the type for body.

Start in the jaxrs-spec generation path that resolves requestBody schemas, comparing it with the existing path-parameter handling for the same $ref enum. Use the supplied OpenAPI document and inspect the generated method; done means the request body is generated as StuffType rather than String.