cannot use epic with a . as payload

[justintim-es]

if i use the epic to map to another action all of a sudden it throws the following error if the payload contains:
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJfaWQiOiI2MDRhMjc5ODNiN2JkMDBjZDA0NmRjYjgiLCJpYXQiOjE2MTU2NjQ3MDd9.BjiO_QZ-LqdIjvnlso4oA_LLsvkPiH66oyVVQIz0hbc
here's my epic but first it worked without any problem but all of a sudden it doesn't accept an epic with a token nomore

export const loginEpicFetch = (action: Observable<IAction<any>>): Observable<IAction<any>> => {
  return action.pipe(filter(ac => ac.type === RDX_LOGIN_FETCH),
  switchMap(ac => instance.post('/api/accounts/login', ac.payload).then(res => {
    const token = res.headers['x-auth-token'];
    console.log(token);
    return {
      type: RDX_LOGIN_FETCH_SUCCESS,
      component: ac.component,
      payload: {
        token: token,
        address: res.data
      }
    }
  }).catch((err: AxiosError) => {
    return {
      type: RDX_LOGIN_FETCH_ERROR,
      component: ac.component,
      payload: err.response.data
    }
  })));
};