TanStack Start SSR + Cookie Auth Issue - Need Advice

// This fails during SSR
export const Route = createFileRoute("/__root")({
  beforeLoad: async ({ context }) => {
    // :x: No cookies available here
    await context.queryClient.ensureQueryData(meOptions());
  },
});

// isomorphic-client.ts
import { createIsomorphicFn } from "@tanstack/start";
import { getHeaders } from "@tanstack/start/server";
import { Api } from "./api-gen"; // swagger-typescript-api

const getServerHeaders = createIsomorphicFn()
  .client(() => ({}))
  .server(() => {
    const headers = getHeaders();
    return headers.cookie ? { Cookie: headers.cookie } : {};
  });

export const apiClient = createIsomorphicFn()
  .client(() => {
    return new Api({
      baseUrl: import.meta.env.VITE_BASE_API_URL + "/api/user",
      baseApiParams: { credentials: "include" },
    });
  })
  .server(() => {
    const serverHeaders = getServerHeaders();
    return new Api({
      baseUrl: process.env.VITE_BASE_API_URL + "/api/user",
      baseApiParams: {
        credentials: "include",
        headers: { ...serverHeaders }, // Forward cookies
      },
    });
  })();

// Before
import { apiClient } from "../api/api-client";
// After
import { apiClient } from "../api/isomorphic-client";