`c.req.json()` makes my POST endpoint hang and timeout

{
  plugins: [
    build({
      entry: "./src/server/index.ts",
      vercel: {  // tried without this, still hangs
        function: { shouldAddHelpers: false },
      },
    }),
  ],
  resolve: { alias: { "@": path.resolve(__dirname, ".") } },
}

import { Hono } from "hono";
import { appBridge } from "@/src/server/app-bridge";
import { connect } from "@/src/server/connect";
import { folders } from "@/src/server/folders";
import { oAuth } from "@/src/server/o-auth";
import { settings } from "@/src/server/settings";
import { translate } from "@/src/server/translate";

const app = new Hono().basePath("/api");

app.route("/app-bridge", appBridge);
app.route("/o-auth", oAuth);
app.route("/connect", connect);
app.route("/folders", folders);
app.route("/translate", translate);
app.route("/settings", settings);

export default app;

import { Hono } from "hono";
import { verifyAppBridgeToken } from "@/src/server/lib/app-bridge";

export const appBridge = new Hono();

appBridge.post("/", async (c) => {
  const { token } = await c.req.json();  // hangs here, I tried on other endpoints, whenever I call c.req.json() it hangs. Works fine locally.:fire: :fire: 
  const res = await verifyAppBridgeToken(token);
  return c.json(res);
});