I’ve been working on a project intermittently for some time now. Recently, after transitioning to a new computer, and router none of my endpoints respond

I’ve taken several troubleshooting steps including:

• Deleting node_modules and reinstalling dependencies with npm.
• Adjusting inbound and outbound firewall rules for ports 27016.
• Attempting to app.listen on ports 27016 and 27017 in my application
  setup.
• Starting a new project from scratch.
• Adding extensive console logging for debugging purposes.
• Successfully connected to MongoDB database using the exact URI via MongoDB Shell and VS Code extensions;
• the initial connection in my app.js is established, and I can list databases
  and collections without issue.

However, the mongoose connection to mongodb appears to “drop” unexpectedly when I make requests to my endpoints via postman.

//User.find and User.findOne timeout
router.get('/all', async (req, res) => {
  try {
    // Fetch all users
    const users = await User.findOne({});
    console.log(users);
    // Respond with the list of users
    res.send(users);
  } catch (error) {
    console.error('Error fetching users:', error);
    res.status(500).json({ error: error.message });
  }
});

“error”: “Operation users.findOne() buffering timed out after 10000ms”

  router.get('/check-connection', async (req, res) => {
  try {
    console.log('working')
    console.log(mongoose.connection)
    // Ensure the connection is established
    if (mongoose.connection.readyState !== 1) {
      throw new Error('MongoDB connection not established');
    }
    
    // Perform a basic query to the MongoDB server
    const result = await mongoose.connection.useDb.admin().ping();
    console.log('MongoDB Ping Result:', result);
    res.status(200).send('Connection to MongoDB is successful');
  } catch (error) {
    console.error('Error pinging MongoDB:', error);
    res.status(500).json({ error: 'Error connecting to MongoDB: ' + error.message });
  }
});

“error”: “Error connecting to MongoDB: MongoDB connection not established”
Error pinging MongoDB: Error: MongoDB connection not established

Your insights on resolving this issue would be greatly appreciated.
more code below:
My app.js
https://playcode.io/1945377

my basic router – users.js
https://playcode.io/1945378