I am building an app that uses NextAuth for authentication. I am using the app router with Next.js. I have a route handler in which I am relying on a getServerSession call to authenticate the user before effectuating an update operation to the database. This works just fine locally. It returns the session for the authenticated user and then, the update operation runs smoothly. However, in the Vercel deploy, getServerSession returns null. Does anyone know why this is happening?

I have read through numerous posts where others have run into the same issue. However, none of the stated solutions have worked for me. It's worth noting that the getSession calls I am making work as expected both locally and deployed.

Here is the actual route handler:

// CREATE ORDER
export async function POST(req: NextRequest) {
  // const session = await getAuthSession();
  const session = await getServerSession(authOptions);
  console.log("session: ", session);
  const token = await getToken({ req, secret });
  console.log("token: ", token);

  if (session) {
    try {
      const body = await req.json();

      const order = await prisma.order.create({ data: body });
      return new NextResponse(JSON.stringify(order), { status: 201 });
    } catch (error) {
      console.log(error);
      return new NextResponse(
        JSON.stringify({ message: "A server error has occurred" }),
        { status: 500 }
      );
    }
  } else {
    return new NextResponse(
      JSON.stringify({ message: "You are not authenticated!" }),
      { status: 401 }
    );
  }
}