@slack/bolt version

3.21.1

Your App and Receiver Configuration

e.g. const myApp = new App({ ... what options are you using? })

const app = new App({
  token: env.SLACK_BOT_TOKEN,
  socketMode: true,
  appToken: env.SLACK_APP_TOKEN,
  logger,
  logLevel: env.LOG_LEVEL,
  customRoutes,
  port: env.APP_PORT,
});

Node.js runtime version

v20.17.0

Steps to reproduce:

N/A

Expected result:

No unexpected disconnection errors

Actual result:

Regular disconnection errors:

Unhandled event 'server explicit disconnect' in state 'connecting'.

Here's the stack trace from Sentry

and the latest error history

Requirements

After upgrading Bolt.js from 3.19.0 to 3.21.1, we started receiving disconnection errors multiple times daily on various environments (prod and testing) of projects that use the Socket Mode.
At least one of those projects didn't have any other logic and/or infrastructure changes.

It looks like there's an error was introduced in one of the latest updates. Could you please confirm the issue or suggest where to dig if it's on our side?