OAuth sign in not working properly in production hosted on Vercel

import { createMiddlewareClient } from "@supabase/auth-helpers-nextjs";
import { NextResponse } from "next/server";
import type { NextRequest } from "next/server";

export async function middleware(req: NextRequest) {

  const res = NextResponse.next();
  
  const supabase = createMiddlewareClient({ req, res });
  const {
    data: { session },
  } = await supabase.auth.getSession();

  route
  if (
    req.nextUrl.pathname === "/signin" ||
    req.nextUrl.pathname === "/" ||
    req.nextUrl.pathname === "/onboarding"
  ) {
    return res;
  }

  if (session) {
    if (session.user.user_metadata.onboarded) {
      return res;
    } else if (!session.user.user_metadata.onboarded) {
      const redirectUrl = req.nextUrl.clone();
      redirectUrl.pathname = "/onboarding";
      redirectUrl.searchParams.set(`redirectedFrom`, req.nextUrl.pathname);
      return NextResponse.redirect(redirectUrl);
    }
  }
  const redirectUrl = req.nextUrl.clone();
  redirectUrl.pathname = "/signin";
  redirectUrl.searchParams.set(`redirectedFrom`, req.nextUrl.pathname);
  return NextResponse.redirect(redirectUrl);
}

export const config = {
  matcher: [
"/((?!api|trpc|_next/static|_next/image|favicon.ico).*)",
  ],
};