Node.js random NJS-040 connection request timeout error

Question

I'm running a node.js app and randomly I'm getting the NJS-040 connection request timeout. Request exceeded queueTimeout of 60000 error. My code feels correct, and I can't seem to find any reason for the error to appear. Furthermore the error doesn't happen at any specific times - sometimes it works for over a day, sometimes it crashes after few hours. When it happens the only way to make it work is to manuallt stop and restart the app.

Heres my Oracle DB configuration:

const oracledb = require("oracledb");


exports.initOracle = async function init() {
    try {
        // Optional param to provide oracle bin for nodejs
        oracledb.initOracleClient({ libDir: "C:\\instantclient_21_10"});
        await oracledb.createPool({
            user: process.env.ORACLE_USER,
            password: process.env.ORACLE_PASSWORD,
            connectString: process.env.ORACLE_STRING,
            poolAlias: process.env.ORACLE_POOL,
            poolMin: 1,
            poolMax: 30,
            poolIncrement: 1,
            poolTimeout: 10
        });
        console.log("Oracle connection pool started");
    } catch (err) {
        console.error("init() error: " + err.message);
    }
};

exports.closePool = async function () {
    try {
        const pool = await oracledb.getPool(process.env.ORACLE_POOL);
        await pool.close();
    } catch (err) {
        console.log("Error occur while closing pool: ", process.env.ORACLE_POOL);
    }
};

And thats the function that console shows its causing the problem:

//Search for patient in oracle
exports.getPatient = async (req, res, next) => {
    let result;
    let pesel = req.body.pesel;

    // console.log('incoming pesel '+pesel)

    let conn;
    try {
        conn  = await oracledb.getConnection(process.env.ORACLE_POOL);

        result = await conn.execute(
            "SELECT id, imie, nazw, pesl FROM pacj WHERE pesl=:pesel",
            { pesel: pesel },
            { outFormat: oracledb.OBJECT }
        );
        if (result.rows.length !== 1) {
            res.status(400).send({
                message: "Patient not found in Oracle DB",
            });
        } else {
            res.locals.patient = {
                patientId: result.rows[0]["ID"],
                firstname: result.rows[0]["IMIE"],
                lastname: result.rows[0]["NAZW"],
                pesel: result.rows[0]["PESL"],
            };
            next();
        }
    } catch (err) {
        console.error(err);
        res.status(500).send({
            message: "Something went wrong while searching for patient query",
        });
    } finally {
        if (conn) {
            try {
                await conn.close();
                console.log("getPatient finally closed connection")
            } catch (err) {
                console.error(err);
            }
        }
    }
};

According to console the source of error is is this line of code:

conn  = await oracledb.getConnection(process.env.ORACLE_POOL);

However I don't see anything wrong here. Any suggestions how to fix the problem?

I've tried moving the await conn.close(); function from finally to inside the if/else loop, but that didn't do anything. I've also added the console.log("getPatient finally closed connection") inside the funally clause to see if it's working - and it seems to be closing the connection correctly.