Problem updating multiple documents on different collections

I am having some problems making data updates of different documents in different collections.
My code runs from a NodeJS-based server.

This is the part of the code that calls the two document update functions:

function delete_game(game) {
  games = games.filter(item => item !== game);
  db.update_listing(game.game_id, {
    p1_score: game.p1.score,
    p2_score: game.p2.score,
    moves: game.moves,
    winner_id: game.winner_id
  }, "game");
  // Update player statistics based on last game (MMR, FILLED CELLS etc)
  db.update_listing([game.p1, game.p2], null, "player_game");
  game = null;
  console.log(`Game deleted. New active game count is: ${games.length}`)
}

While this is the part of the code that deals with performing the functions inherent in the database:

async update_listing(_id_listing, _new_listing, _type) {
        let result = null;
        let update_completed = false
        try {
            // Connect the client to the server
            await client.connect();
            // Establish and verify connection
            await client.db("admin").command({ ping: 1 });

            switch(_type) {
                case "player":
                    result = await client.db("game_data").collection("players").updateOne({ _id: ObjectId(_id_listing) }, { $set: _new_listing });
                    console.log(`Sono stati aggiornati ${result.modifiedCount} documenti.`);
                    update_completed = result.modifiedCount > 0 ? true : false;
                    break;
                case "game":
                    result = await client.db("game_data").collection("games").updateOne({ _id: ObjectId(_id_listing) }, { $set: _new_listing });
                    console.log(`Sono stati aggiornati ${result.modifiedCount} documenti.`);
                    update_completed = result.modifiedCount > 0 ? true : false;
                    break;
                case "player_game":
                    for (let i = 0; i < _id_listing.length; ++i) {
                        result = await client.db("game_data").collection("players").updateOne({ _id: ObjectId(_id_listing[i].id) }, { 
                            $inc: {
                                filled_cells: _id_listing[i].filled_cells,
                                stolen_cells: _id_listing[i].stolen_cells,
                                closed_lines: _id_listing[i].closed_lines
                            },
                            $set: {
                                mmr: _id_listing[i].mmr
                            }
                        });
                        console.log(`Sono stati aggiornati ${result.modifiedCount} documenti.`);
                        update_completed = result.modifiedCount > 0 ? true : false;
                    }
                    break;
                default:
                    break;
            }
        }
        catch (e) {
            console.log(e);
            return null;
        }
        finally {
            // Ensures that the client will close when you finish/error
            await client.close();
            console.log("DB disconnected successfully to server");
        }
        return update_completed;
    }

Unfortunately, if I run the code the document updates are not executed, and in my server console I get the error “PoolClosedError [MongoPoolClosedError]: Attempted to check out a connection from closed connection pool.” However, the connection to the db is opened and closed correctly.

Can anyone tell me where I am going wrong? Unfortunately, I am a neophyte in using MongoDB and surely this problem is caused by my error in handling the communication with the db.

Open/create a client at the start of your application and don’t close it until the application exits, use this client throughout the application.

The driver itself will maintain a connection pool.

My application runs a multiplayer online game. Are you advising me to start a database connection when I start the server, and leave it always on until I stop the server one day to close the game?

I am new to using Mongo DB, but I thought it was a good idea to open and close the connection to the db only when needed so as to avoid “intrusions.”