Backend routes starts with api is served by next router

[rajatdhoot123]

Bug report

Client-side routes are served by the custom node server

Describe the bug

Here is my custom server code

const express = require("express");
const next = require("next");

const port = parseInt(process.env.PORT, 10) || 8080;
const env = process.env.NODE_ENV;
const dev = env !== "production";
const app = next({ dev });

const handle = app.getRequestHandler();

let server;
app
  .prepare()
  .then(() => {
    server = express();

    server.all("*", (req, res) => handle(req, res));

    server.listen(port, err => {
      if (err) {
        throw err;
      }
      console.log(`> Ready on port ${port} [${env}]`);
    });
  })
  .catch(err => {
    console.log("An error occurred, unable to start the server");
    console.log(err);
  });

My backend routes start from /api/**

When I am accessing the server-side rendered page it was working properly.
But when I am making routing on client side it was broken don't know what is wrong here.
One Observation even when I am trying to hit backend routes through the browser it was assuming it as next js app and there was no route match it was returning 404.

Expected behavior

It should not consider backend routes as next js app

Screenshots

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System information

• OS: [e.g. macOS, Windows]
• Browser (if applies) [e.g. chrome, safari]
• Version of Next.js: 9.4.2
• Version of Node.js: v10.19.0

Additional context

Add any other context about the problem here.

[tcelestino]

There's a discussion about it. #9872