await agenda.start() waits infinitely while connecting using an existing MongoClient instance

[ShresthBhimrajka]

I am trying to connect agenda using an existing client but it is stuck on await agenda.start().
Here is the code snippet which is a representation of how I'm trying to initialize agenda

client.connect().then(async () => {
    agenda = new Agenda({ mongo: client.db('agenda-test') });
    agenda.define('updateDoc', { lockLifetime: 10000 }, updateHandler);
    await agenda.start();
    console.log('Agenda started');
    console.log(agenda);
});