Route params not filling successfully in nested api controller files using "mergeParams: true"

[PaulBitplex]

I am implementing Swagger into an ExpressJs project and there is aparticular nessted route that is not filling dynamic route params at all and the request is being sent through like: http://localhost:4900/v2/mines/455/positionpermissions/position/%7BpositionId%7D/group/%7BroleId%7D

This controller is successfully working in a production application and the controller is successfully filling these params both in requests from the front end project and also hitting the api directly in Postman, both returning a successful 200 response. I have checked my JsDocs to ensure naming is uniform across the controller and the jsdoc.

Swagger-ui-express v5.0.0 swagger-jsdoc v6.2.8 ExpressJs v4.16

we are using const router = express.Router({ mergeParams: true }); in the parent controller file. Could this be a problem with how Swagger uses this?

Here is my jsdoc code:

  @swagger
  /v2/mines/{mineId}/positionpermissions/position/{positionId}/group/{roleId}:
    post:
      summary: Assign a role to a position within a specific mine
      description: |
        Assigns a specified role to a position within a mine. This action requires the user to have the permission to add groups within the mine context.

        Permissions Required
        - `MinePermissions.ADD_GROUP`
      tags:
        - Mines/PositionPermissions
      security:
        - bearerAuth: []
      parameters:
        - in: path
          name: mineId
          required: true
          schema:
            type: string
          description: The unique identifier of the mine.
        - in: path
          name: positionId
          required: true
          schema:
            type: string
          description: The unique identifier of the position within the mine.
        - in: path
          name: roleId
          required: true
          schema:
            type: string
          description: The unique identifier of the role to assign to the position.
      responses:
        200:
          description: Role successfully assigned to the position.
        400:
          description: Bad request, due to missing or invalid parameters.
        403:
          description: Forbidden, the user does not have the required permissions to assign roles.
        500:
          description: Internal server error due to a problem with the server.

And here is the controller code, listed in the same folder.

router.post('/position/:positionId/group/:roleId', async function (req, res) {
    // @ts-ignore mineId is defined in mines/index.js and get the value by mergeParams within router
    const mineId = req.params.mineId;
    const positionId = req.params.positionId;
    const roleId = req.params.roleId;
    const userId = req.customUser.id;

    // rest of controller code here
});

I have a GET request in this same file that does not use the extra parameters, and it is working fine, so I am confident the import in my app.js is fine