I try to redirect a user to "/" after authorizing, I have tried alot but it seems to be whenever a redirect happens..

import { NextRequest, NextResponse } from "next/server";
import addUserToDb from "@/utils/functions/addUserDb";
import getDiscordUserInfo from "@/utils/functions/exchangeDiscordToken";
import jwt from "jsonwebtoken";
import redis from "@/utils/connections/redis";
import session from "@/utils/functions/sessionCookieEncryptions";
import { type RESTGetAPIUserResult } from "discord-api-types/v10";

export async function GET(req: NextRequest) {
  const code = req.nextUrl.searchParams.get("code");
  const type = req.nextUrl.searchParams.get("type");

  if (!code || !type) {
    return NextResponse.json({ error: "Missing authorization details." });
  }

  let res, userInfo, setCookies = false, cookieData = "";

  if (type === "discord") {
    userInfo = await getDiscordUserInfo(code).catch((err) => {
      if (err.message.includes("400")) {
        res = NextResponse.json({ error: "Invalid authorization code." });
      }
    });

    if (!res) {
      userInfo = null;
    } else {
      const userId = await (async (user: RESTGetAPIUserResult) => {
        try {
          if (!user) return null;
          const { status, userId } = await addUserToDb({ type: "discord", user });
          return (status && userId) ? session.encrypt(userId) : { status, userId };
        } catch {
          return null;
        }
      })(userInfo);

      if (typeof userId === "string") {
        setCookies = true;
        cookieData = userId;
      } else {
        const errCode = `${Math.random()}${Date.now()}`;
        await redis.set(`forum:error:${errCode}`, JSON.stringify(userId), { EX: 86400 });
        res = NextResponse.redirect(new URL(`/error.php?code=${errCode}`, process.env.NEXT_PUBLIC_URL_ENV));
      }
    }
  }

  if (!res) res = NextResponse.redirect(new URL("/", process.env.NEXT_PUBLIC_URL_ENV));

  if (setCookies) {
    res.cookies.set("session", jwt.sign(cookieData, process.env.COOKIE_SECRET!), {
      httpOnly: true,
      secure: process.env.NODE_ENV === "production",
      path: "/",
      domain: process.env.NEXT_PUBLIC_URL_ENV!.replace(/https?:\/\//, "").replace("/", ""),
      maxAge: 172800,
    });
    redis.set(`session:forum:${cookieData}`, Date.now().toString(), { EX: 172800 });
  }

  return res || NextResponse.json({ error: "An unexpected error occurred." });
}

This code is abit messy, but this is the principle. I have looked at this for a while and still dont understand where it goes wrong. It works when I push the code to my production server, which uses cloduflare tunnels. the server for dev is pointed to local.mydomain.tld, which is just 127.0.0.1

Ping me if you write something, as I dont check very often 😄