Reflexive relashiption jsonapi

Hi, I have a jsonapi:

In my member model: it’s reflexive relationship I expect that the direct_reporting_employees is mapping to directReportingEmployees but I got: Uncaught TypeError: Cannot read property ‘_relationships’ of undefined it means in var relationship = this._internalModel._relationships.get(key); the this._internalModel is undefined anyone has experience with this problem? I did search but nothing work Thanks