Why is my Stripe live webhook not triggering in my Next.js app on Vercel?

I'm experiencing an issue where my Stripe webhook works perfectly in test mode but fails to trigger in live mode for my Next.js project deployed on Vercel. I updated all API keys and the webhook secret, created a new live endpoint in Stripe, and updated my environment variables accordingly. However, I see no webhook traffic or error logs from Stripe or Vercel.

I'm wondering if there's any additional configuration required on Vercel when switching from test to live mode.

Below is my webhook code:

TYPESCRIPTCopied
"use server";
import { db } from "@/firebase";
import { stripe } from "@/lib/stripe";
import { sendEmail } from "@/lib/utils";
import { userDataInterface } from "@/types";
import {
  arrayUnion,
  collection,
  doc,
  getDoc,
  getDocs,
  increment,
  query,
  updateDoc,
  where,
} from "firebase/firestore";

export async function POST(req: Request) {
  const body = await req.text();

  const signature = req.headers.get("stripe-signature");

  let event;

  try {
    event = stripe.webhooks.constructEvent(
      body,
      signature,
      process.env.STRIPE_CONNECT_WEBHOOK_SECRET as string
    );
    console.log(event.type);
  } catch (error) {
    console.log(error);

    return new Response("webhook error", { status: 400 });
  }

  switch (event.type) {
    case "account.updated": {
      const account = event.data.object;
      const q = query(
        collection(db, "users"),
        where("connectedAccountId", "==", account.id)
      );

      let userUID;

      const data = await getDocs(q);
      data.forEach((doc) => {
        userUID = doc.id;
      });

      if (userUID) {
        const userRef = doc(db, "users", userUID);
        const statsRef = doc(db, "another", "stats");

        await updateDoc(userRef, {
          stripeConnectedLinked:
            account.capabilities?.transfers === "pending" ||
            account.capabilities?.transfers === "inactive"
              ? false
              : true,
        });
        await updateDoc(statsRef, {
          developers: increment(1),
        });
        break;
      } else {
        console.log("No user found!");
      }
    }
    case "checkout.session.completed": {
      const session = event.data.object;

      try {
        const userId = session.metadata.userId;
        const userEmail = session.metadata.userEmail;
        const productId = session.metadata.productId;
        const ownerUID = session.metadata.ownerUID;

        if (userId && productId) {
          const userRef = doc(db, "users", userId);
          await updateDoc(userRef, {
            lastPurchaseToken: session.id,
            boughtProducts: arrayUnion(productId),
          }).then(async () => {
            sendEmail({
              to: userEmail,
              subject: "Thank you for your Order!",
              type: "successful-order",
            });
          });

          const productRef = doc(db, "products", productId);
          const statsRef = doc(db, "another", "stats");

          await updateDoc(productRef, {
            sales: increment(1),
          }).then(async () => {
            const docRef = doc(db, "users", ownerUID);
            const docSnap = await getDoc(docRef);

            if (docSnap.exists()) {
              const data = docSnap.data() as userDataInterface;

              sendEmail({
                to: data.email,
                subject: "Great news! You've just made a new sale on MiPa!",
                type: "new-sale",
              });
            }
          });
          await updateDoc(statsRef, {
            downloads: increment(1),
          });
        } else {
          console.error("Missing userId or productId in session metadata");
        }
      } catch (error) {
        console.error(
          "Error updating Firestore for checkout.session.completed:",
          error
        );
      }
      break;
    }
    default: {
      console.log("unhandled event");
    }
  }

  return new Response(null, { status: 200 });
}

I appreciate any help in troubleshooting why the webhook isn’t being fired in live mode.